My surgery was six months ago now, and things are going pretty well! After I had no more limitations in terms of training volume and intensity, I stacked eleven 20h+ weeks on the bike. I believe this to be completely responsible. Why? Because if you’ve had 25 consecutive rest days, that still averages out to two rest days per week for the following 11 weeks or one rest day per week for the next six months.

Of course, that is complete nonsense, but I like to justify ridiculous training schedules. In Dutch we call this talking straight what is curved. You’re basically trying to put a good spin on something that is bad or crooked. Politicians do it on a daily basis, so I can as well. I well on my way to being in my best shape of the year by December. This is completely useless, but I will earn myself the Christmas Champion title and I am proud of it.

New leg, new me

But thanks to – or despite – this (over)training schedule, things are going pretty well. I will write in more detail on my experiences on the full recovery process in a separate post. The first months after surgery were pretty rough. Since October, though, I’ve started to feel better and the power has come back. I also took the opportunity to reset myself, not only physically but mentally as well. With nothing to lose and things only able to get better, I dropped bodyweight restrictions and committed fully to becoming a more powerful rider.

I doubled down on strength training. I am playing Ronnie Coleman 2x per week now. I’ve done strength training before, but never liked it. It felt like it only fatigued me without showing results on the power meter. This time is different. I have broken all my power PRs over the past month. A huge mental relief: it proves that the surgery was successful, but also that the gym work is effective.

For the latter, I attribute a lot to diet. To actually get stronger from the strength work you’re doing, you need to fuel it properly. You can’t lift heavy weights, do your intervals, and ride 20 hours per week while only eating just enough to sit at maintenance. No, you need to stuff your face. You need to look at your enormous bowl of oats and ask yourself: do I really need to eat all of that? Yes. Because it will make you strong as f*ck. The mindset should be to eat the amount that will make you stronger, not the amount that will prevent you from gaining weight.

In our weight-obsessed sport, it can be hard mentally to gain 5 kg and need to upsize your cycling kit. But then again, having a 410 W FTP is also pretty cool, aye. And I started using creatine, so it’s all water weight anyway… isn’t it? 😉

Happy Christmas, you filthy animal

So all the bad comes with something good. 2025 was not the best year, but I believe I’ve come out better mentally and physically. 2026 will be a good year on the bike. Regarding New Year’s resolutions, I don’t have any. I’ll just try to keep reminding myself of the lessons learned over the past months. And training responsibly?

Maybe in 2027.

Wishing you a Happy Christmas and all the best for 2026.

Subscribe now

Last time, I left off at how to self-diagnose signs of iliac artery endofibrosis. That’s a great starting point for picking up early clues. However, to get a proper diagnosis, you’ll need to go to a hospital for specialized imaging. And I want to emphasize specialized. Iliac artery endofibrosis is a strange animal – it’s not a typical arterial disease. The symptoms often only appear under specific conditions: certain positions, high load and effort. That means you need to find a clinic with experience diagnosing cyclists, one that tailors its approach to your use case (you, the cyclist.)

MRI and Doppler

In both the Netherlands and Belgium, there are several hospitals with expertise in diagnosing iliac artery endofibrosis. Without diving into a review of each one – this isn’t meant to be a healthcare rating blog– I’ll just share my own experience: I was treated at the Flevoziekenhuis in Almere. Their diagnostic process included Doppler imaging and an MRI scan. In some clinics, they also incorporate exercise tests combined with blood pressure measurements. This approach is actually quite similar to the self-assessment I did earlier – just a bit more ‘sophisticated,’ of course.

Doppler imaging

During Doppler imaging, ultrasound is used to visualize blood flow in your arteries. The setup is quite similar to a prenatal ultrasound. However, instead of checking whether the baby has her nose or his nose, they’re looking for restricted blood flow. I highly suggest you bring your partner (if you have one). If you weren’t worried about your arterial health, it would almost be a romantic moment.

The imaging process involves checking your arteries in different positions: with your legs straight, at a 90-degree angle, and after some physical effort (in my case, 1–2 minutes of squats). The goal is to recreate the conditions under which you would experience symptoms while cycling. With your legs straight, blood flow is smooth and steady. At a 90-degree angle, a kink in the artery may cause turbulence. After exercise, this effect becomes more noticeable. They scan both the left and right sides and know exactly what flow patterns are normal and what patterns raise red flags.

MRI

Doppler ultrasound is usually the first step and often gives a strong indication if something is wrong. However, to pinpoint the exact location of a narrowing or kink in the artery, I underwent an MRI scan. During the MRI, they inject contrast fluid into your veins. This helps to clearly show your arteries and blood flow. They perform the scan both in a straight position and a fetal position. The fetal position mimics a cycling posture, which is when the kink or narrowing often becomes visible. In a straight position, everything might look normal.

That’s exactly why you need to see a specialist. Standard imaging can easily miss the issue if not done in the correct posture or with the right technique.

The confirmation you were looking for

After the imaging is done, your doctor or surgeon will go over the results with you. In my case, I was shown the imaging of the kink in my artery, which is pretty cool actually. You see a visualization of your blood squeezing its way through the kinked section. This visual also left me with no doubt. Even with zero medical training, I could clearly see something was wrong. It looked like someone had twisted a garden hose. Poor leg.

The MRI doesn’t just confirm the issue. It also helps to pinpoint the exact location of the kink and helps to make a plan for surgery, which I’ll cover in the next post of this series.

Thanks for reading again, kisses from Watopia.💋😘 I’ve already done my first spins back on the bike, and it feels amazing to move again.

Subscribe now

One kink to destroy it all

The nature of iliac artery endofibrosis – let’s go with EIAE from now on – in athletes makes it difficult to detect. At rest, everything appears normal, but during efforts, symptoms emerge. The artery supplying blood to the leg becomes narrowed and cannot meet the increased demand for blood flow.

When in tucked cycling position, which reduces the hip angle, symptoms often worsen. This smaller hip angle creates a kink in the artery, further restricting blood flow. In fact, it is this repeated kinking that initiates the development of endofibrosis, as the constant compression and stretching damage the artery’s inner lining. Over time, scar tissue forms, progressively narrowing the artery even more. Because this process repeats with every pedal stroke, EIAE tends to worsen if you continue cycling without intervention.

Self-diagnosis – DIY blood pressure testing

When there’s a narrowing in the artery, less blood can get through. During exercise, your muscles need a lot more blood. But because the artery is partly blocked, it can’t deliver enough, so the pressure past the narrowed area drops. Think of it like squeezing a garden hose: water pressure goes down on the other side of the pinch. And exactly this pressure drop you can measure yourself pretty easily! And that is exactly what I did. All you need is a blood pressure monitor with a small cuff that fits your ankle.

It’s important to take these measurements after intense effort, since that’s when your blood demand is highest – and when any pressure drop will become most obvious. Here’s how I did it:

1. Ride 6min at 95% of FTP.

2. Get off the bike asap, lay down flat on your back (e.g. all limbs are on the same level as your heart)

3. Measure BP at the arm.

4. Measure BP at the leg.

You’ll want to perform all these steps as quickly as possible. After exercise, blood pressure levels can normalize within just a few minutes, so if you wait too long, you might miss the pressure drop entirely or end up with a false positive. Ideally, you would use two blood pressure monitors to measure your arm and leg pressures simultaneously (I didn’t).

It’s also best to test both legs, so you can compare the results side by side. Once you’ve collected your measurements, you can calculate the Ankle-Brachial Index (ABI) for each test to help interpret your results. If you’re interested in more in-depth information about how EIAE affects blood pressure, I recommend read this study and this study.

I performed four measurements myself, which you can see in the table below. Ideally, I would have measured even faster, since blood pressure levels start returning to normal within moments after stopping exercise. By the time I measured my leg, the values were probably already partially recovered. Still, the consistently low ABI in my left leg, along with the clear difference between my left and right leg results, convinced me to seek expert help for EIAE.

Obligatory disclaimer

Of course, doing this kind of self-test is no substitute for a professional medical diagnosis. But it can help ease your mind or give you that extra push to take action when it’s needed.

In my next post, I’ll cover the second part of the diagnostic process: the tests you’ll undergo at the hospital and why it’s so important to find a hospital or clinic that specializes in this type of injury in athletes. I hope this deeper dive was helpful! Feel free to subscribe and follow along on this topic!

Subscribe now

Pick up the vague stuff early

The symptoms pinpoint why an early diagnosis is so challenging. They tend to be vague and inconsistent. The classic symptom of one leg giving out when riding above your FTP might not be that apparent, especially in the early stages. Looking back, I think first signs appeared about six months ago, long before I ever considered artery problems. You could see these as early warning signs, although they might not mean anything on their own. Then there are red flags that should raise concern, along with obvious indicators that become easy to recognize once you know what to look for. Finally, there’s the weird stuff I experienced, which may or may not be related. Let’s break them down.

Early warning 🧐

• Unexplained inconsistency – alright this might not be an actual symptom, but it’s still important. Coming into key sessions or race days well-rested yet underperforming can be a sign. Of course, everyone has off days where the legs just don’t show up, but if it happens repeatedly, it’s worth taking a closer look at what’s going on. Keep in mind that if you’re unaware of a unilateral problem, you might not even realize that one leg is actually responsible for the issue.

• Only one bullet – in races, my single-effort power was still solid, but I struggled with repeated efforts. This was probably because one leg wasn’t able to recover as it should, leading to an overall decline in performance. Remember when I wrote about my ‘mentally failing’ in races. I have second thoughts on this one now.

Red flag 🚩

• Unsymmetrical post-ride recovery – this stood out to me even more than the differences I noticed while riding. After hard or long sessions, I consistently felt more muscle soreness and heaviness in my left leg compared to my right.

• Tingling sensations – during long rides, I experienced tingling, particularly in my lower leg and shin.

Obvious 🆘

• Constant urge to stand up – I became much more aware of this behavior after doing my blood pressure tests. During longer tempo efforts, I felt a constant need to stand, even though I normally prefer to ride seated most of the time.

• Aero is the enemy – riding in a tucked position or in the drops while pushing above zone 2 became nearly impossible. My left leg would start to “blow up”, making 280 watts feel more like 400.

Weird Stuff 🤔

• One foot is colder – during winter rides, my left foot often felt slightly colder than my right. There can be many reasons for this, since no one is anatomically perfect, but I suspect it might be related.

• Office chair tingling – if I sat in my office chair for longer periods, especially after a training ride, I would feel tingling in my left foot. It is similar to the numb, pins-and-needles sensation you get after sitting on your hand for too long.

• Stretching numbness – certain stretching positions would trigger numbness and tingling. For example, child’s pose would make my left leg feel numb.

You’re not crazy, but don’t drive yourself crazy either

You will almost always feel something somewhere in your body. When you become hyper-focused on every sensation, whether on or off the bike, it’s easy to convince yourself you have an injury. The key is to identify true asymmetries and abnormalities. Try to recall how things felt a year ago – endofibrosis develops gradually, so sensations that feel “normal” now may actually be abnormal. Its symptoms are often vague and can fluctuate from day to day, creating the perfect recipe for driving yourself crazy.

I’ll cover the diagnosis in the next article of this mini-series, including a more detailed explanation of the blood pressure tests I performed myself and the assessments carried out at the hospital. Thanks for reading!

Subscribe now

But you were going pretty well?

It might seem like yes, but no. First, rule #1: as an athlete you don’t talk about your doubts and weaknesses. Everyone is always bothered by something, whether it is a blister or something more serious. You don’t talk about it so as not to make the competition any wiser – but more importantly, to not talk yourself down. Focusing on the negative will not help your training and only drives you crazy. I am sure you can talk yourself into an injury without actually physically suffering from one.

Second, indeed I was pretty fit. I was training well and my fitness was on a good level. But only relatively speaking. I noticed I was stagnating. I had not progressed over the past half year and started to perform inconsistently during racing and training. But more importantly: I was not feeling well on the bike. Every session felt like ‘working’ to get the power out.

WTF is going on?!

This feeling of inconsistency – the good days, the bad days, with the bad days slowly becoming more dominant – started to make me doubt. WTF is going on?! I am ticking all the boxes, but I only started to feel worse every week. To closer friends and family, I sometimes briefly mentioned the strange feelings in my left leg that started to become apparent, still not really willing to admit it to myself. I made up my own excuses to downplay it, some of the best:

• My fan is on my left side on the indoor trainer, the cold air might affect the blood flow in my left leg

• I switched saddle last year, I will switch back to my old saddle

• I crashed in December 2024, that hurt my leg, it might still bother me

Self-diagnosis to the rescue

Frequent readers of this blog probably know I like nerding around. No different here. I am familiar with iliac artery endofibrosis and also have cycling friends who have had it. However, my problems, especially in the earlier stages were not prominent enough – at least that is what I told myself – to chase a doctor and get a scan. I was displaying ostrich behavior (see excuses above).

Early May I could no longer ignore the sensations in my leg and I started to have a serious suspicion of iliac artery endofibrosis. I started to do more research on how you can diagnose it. Turns out, a simple blood pressure test on your arm/ankle (ABI index) pre- and post-exercise is a good method to detect the presence of endofibrosis. So, I ordered a 30EUR blood pressure device and did the test. The results: no bueno. My blood pressure dropped significantly on my left-leg post exercise – a clear indication of restricted blood flow in the artery. This ‘self-testing’ experiment that was supposed to ease my mind now got my seriously worried.

You are only as strong as you weakest leg

Obviously, next steps were to start finding a doctor. I started asking around and ended up with Jelle Posthuma, a surgeon specialized in treating this condition in cyclists. I explained my situation, symptoms and the results from blood pressure tests. Jelle got me over for a Doppler ultrasound + MRI and the results confirmed what I already feared. My left iliac artery was kinked and narrowed.

Fast forward two weeks, and here I am post-surgery. The past few days were pretty rough, but I am feeling better by the day and will be sure to come back soon. Many thanks already to Jelle and the hospital for helping me so quickly. In the end, you are only as strong as your weakest leg.

I will have quite some time on my hands the coming days and plan to write more on this topic. Iliac artery endofibrosis is relatively common, yet not well understood. Many cyclists waste months/years before they get the right diagnosis. I plan to do a little mini-series to tell you more about my symptoms, diagnosis, recovery, etc. Interested? Hit the subscribe button👇

Subscribe now

In the meantime, let me know if you have any questions on this topic!

There are many misconceptions between e-racers and ‘IRL’ racers (be it road or off-road). Kate Trdin, 2024 Australian e-sports champion, already wrote a great article on The Zommunique, explaining why comparing indoor power output to outdoor power output is like comparing apples to oranges. Kate does a great job explaining why this comparison doesn’t hold up. I am definitely not going to echo Kate’s insights here. Just be sure to read her article!

Road-only and turbo-only don’t understand each other

Kate’s article is mostly about justifying e-racers’ power output. But there is more to it! E-racers and road racers don’t understand each other’s discipline. Some elite e-racers tend to think they’re close to pro level, and road cyclists believe a WT pro would easily win an elite e-sport race.

Most pro cyclists wouldn’t last 30 minutes in a virtual race

Both are wrong. I am pretty confident that many pro cyclists wouldn’t last 30min in a virtual race (hot take!). Lasting in a virtual road race takes serious mental resilience – it hurts from start to finish. There is zero coasting and no peloton elastic to save you. Plus, we never wait until the last climb, it is always complete bananas from the start. The first climbs are usually much faster than the later ones. If you are dropped, you are dropped.

Aaaaand most e-cyclists wouldn’t last 30min in a road race

Similarly, e-cyclists wouldn’t last long in a road race either. Positioning yourself in a peloton, cornering or even taking a gel mid-race. Not that easy when riding bar-to-bar with 180 riders. Nevertheless, many e-cyclists have the illusion that they can just blend in. They see some stats on power output on Instagram and think, ‘I can do that.’ But if you’ve never done it, don’t assume you can.

The power-focused mindset many virtual cyclists have annoys me.

It shows a kind of arrogance and underestimates the skill and fatigue resistance needed for road racing.

Blending both disciplines is definitely possible

This does not mean that road and e-racing do not blend. Quick humble brag: I am pretty handy in a peloton and transition between grinding on a trainer and road dynamics fairly easily. Also, at the pro level, there are guys like Jay Vine and Freddy Ovett. Maybe Vine is a bad example, because many joke he crashes so much “being that guy from Zwift”. Yes, maybe he’s unlucky. But when you see him TT and descend, he can handle a bike.

Long story short: a bit of mutual respect between disciplines is more than appropriate.

After finishing this piece, I realize things are turning a bit more in a personal blog. Hope you enjoyed it anyway. Thanks for reading!

Subscribe now

But redemption never came. Instead, I stepped off the bike mid-race, left in a group with nothing to ride for but a possible 30th place. Nowhere near what I came for. The weather didn’t help either – an average summer day turned miserable: cold, soaking wet, and well outside my comfort zone. So a DNF it was. My hyperfocus on those nationals and the disappointment that followed left me fed up with road cycling.

Finding my happy place on the virtual roads

I found renewed motivation and pleasure in racing online. I turned out to be very good at it, winning races; I was competitive with the best. This opened the opportunity to join the e-racing (aka Zwift) team of Movistar. Pretty cool, probably the I’ll ever get to riding for a WT-team (…or?). I left the road for what it was, my focus was on getting stronger on the trainer. E-racing is even more of a watt game than road cycling. Less about positioning and bike handling, more about raw power and tactics.

Looking back now, this focus on e-racing helped me improve. It exposed my weaknesses. My longer efforts and climbing capabilities have always been good. However, my explosive power – especially sprint to 2-minute efforts – was not good enough. Zwift races are full of point sprints and KOM segments. Even if you can’t win them, you still need to be powerful enough to at least not get dropped! And positioning, something I am rather good at on the road won’t save you on Zwift. So, more raw power was needed and that’s what I have focused on over the last year. I am sure I am a more versatile and stronger rider now than back in 2023-2024 – physically speaking.

That itch is back

As 2025 season started, I felt no urge to step back into road racing. I was still enjoying the indoor race season. Cycling friends kept asking whether I ever got tired of the indoor trainer, the answer was no. I could satisfy my competitive edge in the virtual races and did not need to worry about crashing myself and my bike in the madness of the Dutch ‘clubcompetitie’ for elite riders – it has quite the reputation for pile-ups and crashes. I have raced in multiple countries, but Dutch races are the craziest. I have never been scared, I just felt like it wasn’t really worth the risk.

However, after indoor season had calmed down, things started to itch. I started to become curious how I would do in road races. Did my indoor ventures make me stronger? Strong enough to step up from a good elite to a race winning elite?

Dipping a toe back into it

I decided to sign up for a local road race. Far from the level of the bigger races I’ve done before, but it was the same one where I started road cycling six years ago – just a few categories higher this time. Good vibes, familiar parcours, and no pressure. I was mostly there to have fun. Still, I lined up with the conviction that I was there to win. I thrive when I have this mindset. If I believe I can win, I race my best. But if you show up thinking you can’t, you’ll probably just suffer. Of course, a bit of realism is required. You can be as convinced of yourself as you want, but you’re not winning the Tour de France just by believing in yourself.

Yet, it worked. I stayed in the front ten all race. I jumped when I had to, kept the legs still when I could, and attacked when the bunch was tired. The result? Top step of the podium. Damn, road racing is enjoyable like this!

What’s next?

Unsure, but I’ve stepped back into the kitchen – time to start cooking again. 😉 More on that soon (what a cliffhanger, I know).

For my next post, I’ll dive into some common misconceptions between road cycling and e-racing. There are plenty of biases in both directions. Some elite e-sport riders believe they could go toe-to-toe with the world’s best on the road, while many road cyclists see e-racers as one-hour watt machines, spinning at 60 rpm and unable to corner a real bike. Both views are wrong (although not entirely).

This was a bit of a different post than you are used to. More of me spilling some personal thoughts, lacking the usual training/tech insights. Let me know if you liked it and subscribe!

Subscribe now

1. June 2024 – 4 days off, due to illness.

2. June 2022 – 3 days off, can’t recall the reason.

3. November 2021 – 2 weeks off, coach-prescribed off-season.

It’s clear: I don’t like rest weeks. I simply like riding my bike. A day on the bike is a better day than a day without it. However, this time I decided to be wise: I needed a recovery week including a few days off the bike. I am not much of a believer in the actual benefit of off-seasons or full rest weeks. The general trend in the cycling peloton is also leaning towards shorter periods without the bike. Two-month off-seasons no longer happen. Nevertheless, it’s still common for riders to set the bike aside for a few weeks each year. This is especially relevant in winter and right now, as many riders reset after the first part of the season and shift their focus towards grand tours. What is the idea behind it and why am I off the bike this week? And no, I am not doing a Grand Tour, I wish 😉.

“Bro, I’m on my knees”

Last week wrapped up the last part of the indoor season (NB: it actually goes on throughout summer as well, but there are less races). I was going backwards in my race last weekend – completely cooked. My shape was already a bit up and down over the past months. I had good days but also bad days. Looking back now, I should have stepped back earlier, however that is a tough decision to make when you are mid-season. I was eager to do well every week and didn’t want to break my rhythm. Deep-down I know taking a week off is not going to hurt my shape, yet it is hard to do mentally. Maybe I should have a coach to tell me, but that is another topic in itself (will cover that later!).

I pushed on and found myself absolutely crumbling in the race last Sunday. My legs had had enough, not just for that race but in general. To fellow riders asking me how it went, I replied – semi-jokingly, semi-seriously: “Bro, I’m on my knees”.

Rest/recovery weeks

So, the doctor prescribes a rest week. Or better said: recovery week. A rest week to me is a week that contains no exercise at all, that is pure torture. It does not make me happy neither does it make me feel better. Recovery weeks are easy weeks during which I am still active but take it easier and focus on doing different things than riding the bike. Basically, go with what you feel like doing. Mentally, it’s good to take your mind off the pressure of “having to” ride your bike. But if you feel like? Go for it! Just take it easy. This week, for example, I did nothing for two days and then went for an unplanned run today (day 3). I ended up running 26k, but I enjoyed it, and it felt easy. So why not? And for tomorrow, I don’t know. There’s no plan and that’s the most important part of a recovery week.

There’s no plan and that’s the most important part of a recovery week.

From a pure physical point of view, you will recover within a few rest days. Especially if you don’t go crazy in the remainder of the week, you are (normally) good to go again. Taking it easy for much longer will cost you. The winters during which I have had 2 weeks completely off any exercise made me feel horrible. I could not do what I like most: ride my bike and additionally once you step back on the bike, you feel like cr*p. After which it takes weeks to get back to the level you were at.

The ideal off-season duration

The ideal length of an off-season and/or recovery period is something personal, especially because the mental aspect of it is so important. It is not just about being physically recovered but also being mentally ready to train hard again and chase your goals. However, looking purely at the physical effects it is best to limit the period of inactivity to 1-2 weeks. Some physical changes will start to become significant after this period, a quick grasp:

• VO₂max drops. Up to 20% after 2 months of inactivity; the steepest decline happens in the first 2–3 weeks.

• Endurance capacity (e.g., time to exhaustion) can decline by up to 21% in as little as 2–5 weeks.

• Maximal Heart Rate (HRmax) increases by +2 to +9 beats per minute on short term (<4weeks). You might recognize this: a high HRmax, you are fresh and rested!

• Muscle glycogen stores drop by ~18% in 4 weeks, reducing fatigue resistance and endurance.

  

All taking significantly longer to regain. Knowing this you might want to re-think your 6-week off-season in winter. Cliché but true: fitness arrives on foot and leaves in a Ferrari.

Luckily it is not all that horrible. Most of these effects only become significant after 1–2 weeks. Moreover, maximal strength is largely preserved for 2–4 weeks, and no major hormonal changes occur during this time. On top of that you will be mentally fresh to hit it again after a period of rest.

Conclusion: embrace those rest weeks, it’s not that hard!

If you liked this post, please share and subscribe!

Subscribe now

More is more

For a long time, cycling has been about getting skinnier and eating less. But it's fair to say that this idea is outdated. These days, it’s common knowledge that especially the second – eating less – is not the way to go. Most pro teams now have dedicated nutritionists and use internal food-tracking apps. The general mindset has shifted from ‘eating less’ to ‘eating enough’. Enough to fuel your training and racing while still maintaining a (very) lean physique. Bu takes it a step further: athletes shouldn't just eat enough, they should eat more. Eating more > eating enough > eating less.

This is a very interesting, fresh view on how we have perceived cycling over the past decades. We have indeed seen bigger riders be successful in the recent years. Jonas Ambrahamsen stole the show in the 2024 Tour de France. He wore the polka dot jersey in the first two weeks and was riding in the breakaway day after day after day. He gained even more respect after being openhearted about his weight gain story. But he is not alone. Early this year, we saw another rider from Olav Bu’s Uno-X Mobility team, Søren Wærenskjold, win Omloop Nieuwsblad. He tipped the scales at a whopping 92.3kg on race day. And in Paris-Nice we saw Mads Pedersen – not quite the lightest rider in the pack – climb with the best.

Mass and VO2 Max

That said, we don’t see big guys like Wærenskjold or Abrahamsen play a role in real climbing mountain races. Moreover, the success of both riders is against the general trend in cycling. This study analyzed the Body Mass Index trends for the top five finishers in men’s grand tour and cycling monument races from 1994–2023. Looking at the graphs below, you can clearly see the opposite trend for both the grand tours and monuments.

Riders are getting leaner and lighter. This makes the strong performance of heavy riders even more remarkable. But not according to the philosophy of Olav Bu. He believes that the added power resulting from higher mass can result in superior performance. Even on climbs. From experience with his own athletes he has seen that athletes who gain weight also improve their VO2 max. Hence, it is possible that raw power literally outweighs the performance of super lean athlete.

Let’s get big

Of course there is a limit to this. No 85kg rider will ever win a Grand Tour. But there’s a sweet spot: a weight that matches the type of rider you are/want to be. Looking at myself, I have been around 68-69kg over the past years with an FTP around 380-390W. A power-to-weight ratio that’s kept me competitive (reminder: I focus on e-racing). However, I did still find myself out-powered by other riders. To improve my performance, I have taken a slightly different approach. Putting on a few extra kilograms is part of this.

I realize that this is a non-intuitive step. At 183 cm and 68–69 kg, I’m not exceptionally light for my height – at least not by cycling standards. Intentionally bringing my weight up is a bit of a gamble, especially in a w/kg dominated sport like e-racing. However, so far I am not unhappy. Currently sitting at 71kg, I have raised my FTP above 400W and improved my 5sec, 1min, 5min and 20min power PRs over the past months.

So let’s get big.

If you liked this post, please share and subscribe! Want to know more? Check my previous article about food coach apps.

Subscribe now

Now first, let’s not be over-dramatic. I am framing it here. Failing in a Zwift race – also an elite Zwift World Series race – is not the end of the World. Actually, failing in any sports event is never the end of the world. It’s only sports, the Sun will rise the next day. BUT, if you put your effort and passion into something it is perfectly fine to be disappointed after you did not get what you aimed for.

Believe to succeed

Back to the race – what exactly happened? In short: I stopped believing. After 50km of racing a small group of riders broke away from the peloton. My racing instinct told me no-one was going to ride this back, so I jumped. I bridged to the group and closed the gap just before the final 1.5km uphill drag to the finish line. It was the right decision, the peloton was not really responding – anticipating the final climb and bunch sprint. We got a 10 second lead and I knew the winner was in my group. All good, right?

Yes and no. Here is the problem: I had been in this situation in three previous elite races. And three times I popped just before the finish line, got overtaken by the peloton whereas the winner was in my group. Halfway up the climb, I felt my legs filling up. With that feeling, intrusive thoughts entered my mind: ‘no not again’, ‘you are going to loose it just before the line’ , ‘you can’t hold the wheel of the riders in the break’, ‘the peloton is accelerating, you are losing your lead’. And poof, my legs followed my thoughts and I sat down before I knew it. My group stayed ahead of the peloton, me P25. I failed, again.

Succeed to believe

My legs didn’t fail me, my head did. I stopped believing because I had no success in previous, very similar race situations to make me believe. This is confirmed when looking at the raw data of the final 5 minutes of the race.

I came in rather fresh, you can see that the green graph, my W’ – a measure for how much is left in your anaerobic reserves – was almost completely full. After putting in the initial surge I took out quite a bit, but it was far from empty. After that I continued at a power slightly above my threshold before I sat down. I averaged 420W for the final 5min. For reference: my FTP is 400W and my 5min power is 480W. The conclusion is simple: I could have gone harder.

And of course you will feel your legs at the end of a race after 1 hour of hard racing and putting in a big surge. But that does not mean you can’t continue. I was far from my physical limit. It was my head that stopped me.

Mental aspect of sports

You can be as data driven as you want, have done the numbers 100 times in training – when you are racing it should happen in that moment. It doesn’t matter whether this event is your local park run, a random Zwift race or the Olympics. Overthinking rarely helps. 9 out of 10 times, it hurts. Next time, the only thing I'll be thinking about is not thinking.

Bonus tip: for anyone interested in the mental aspect of suffering, be sure to check out the book How Bad Do You Want It?: Mastering the Psychology of Mind Over Muscle.

If you enjoyed this post, feel free to share and subscribe! More stories coming your way 😉.

Subscribe now

The latter is problematic. For a long time, I have tried (and managed) to limit my caffeine intake. I kept caffeine for races and only allowed myself coffee on study or work days when I really needed the boost. But this turned out to be a sliding scale. Unconsciously I lowered the barrier to drink coffee. I moved from races only to races and key training sessions to all training sessions in general. And if I had the coffee before my training session anyway, why not another one at work after training?

“I did already have 2 coffees before my morning training, the third after lunch doesn’t really matter.” ~me

At this point I have reached a stage where I am literally craving my morning coffee every day. And yes, not having it does lead to occasional headaches. I do have one rule still and that is no coffee after 3.00 PM. But then there is e-racing (Dun Dun DUUUUUUN!).

I have mentioned it a few times in earlier posts that I am an elite e-racer. This means that I am riding my bike indoors and compete in virtual races against riders all across the world. Something I do with great pleasure and passion. The only downside: races are often in the evening. To perform at my best, I do have quite a lot of caffeine pre-race. On a typical racing evening I would have 1 or 2 energy drinks (they tend to be easier on the stomach than coffee) pre-race and another drink or caffeine gel during the race. So ~200mg of caffeine at least.

So much for the no caffeine past 3.00 PM rule. Yes, I have gone down the caffeine drain.

But how bad is it?

Purely looking at the evening races? It’s bad. Caffeine and HIIT late night is the perfect recipe for sleepless nights. I can’t sleep until 3 hours after a race and the sleep that I do have is very light. Research shows that HIIT in general can greatly improve sleep quality, but it is better to avoid late night HIIT sessions. Training late? It is best to keep the intensity low to moderate.

Same for caffeine. Caffeine has many positive effects on your performance and cognition. But stay away from it in the evening. It comes as no surprise that caffeine does mess up your sleep. The closer to bedtime large doses of caffeine are consumed, the greater the reduction in total sleep time. Research showed that:

• To avoid reductions in total sleep time, coffee (107 mg per 250 mL) should be consumed at least 8.8 h prior to bedtime and;

• A standard serve of pre-workout supplement (217.5 mg) should be consumed at least 13.2 h prior to bedtime.

Well, whoops…

Luckily, you can build tolerance against the effects of caffeine. This will probably make you sleep better. Or you will just find yourself having more and pushing you further down the caffeine drain.

Don’t do caffeine, kids. *Unless you want to ride your bike, fast.

Did you like this post, please share and subscribe! Want to know more? Check my prior articles about the effect of supplements on performance and sleep tracking.

Subscribe now

New data unlocked

First off, they are great (nospon). They rarely vary >0.5% from the power readings on my Wahoo Kickr v6 bike trainer. Extremely satisfying. Only recently I discovered (yes I know, you have higher expectations of me🤓), that I need to turn on dual channel in the app to actually get L/R and cycling dynamics data on my Garmin head unit.

So that’s what I did. After doing my first ride with the L/R-balance data I ran into quite a shocker. Left/right-balance: 56/44%. Pardon me. The rides that followed didn’t vary much, each of them showing a consistent 3–4% imbalance between my left and right leg. I already suspected a slight imbalance as my left crank powermeter was always over-reading compared to my Kickr trainer – especially in the lower power regions (an important detail, more on that later). Additionally, I have a small difference in leg length. Nevertheless, 56/44 is beyond what I expected.

How bad is it?

Being the type of person I am, I dove into this. How common is a L/R imbalance and how bad is mine? Some googling soon taught me that 56/44% is definitely on the higher end. But power imbalances are not uncommon. A study among 112 pro cyclists competing in two editions of the Giro d’Italia showed that also among pro cyclists, power imbalances are very common.

It also becomes clear that power imbalance tends to decrease when intensity increases. This is quite common and also a crucial metric you should check when looking into power imbalances. It should even out when you ride harder.

As a good rule of thumb – if there is a difference between legs and this doesn’t improve as you ride harder then it might be a good idea to go and see a good local bike fitter. ~ James Spragg in Cycling Weekly.

That’s also the first thing I checked after seeing my rather big power imbalance. Fortunately, it approaches 51/49 when working on and above my FTP. So I am not too worried about it. Additionally, there are cyclists noting that their imbalance evens out as fatigue (e.g. duration of the ride) increases.

Can (and should) I be fixed?

There are multiple ways to fix power imbalances. Single leg drills on the bike, mobility exercises, targeted strength training and working with professionals like physiotherapists and bike fitters can help. I will look into these options! It is not likely that I will ever be a perfect 50/50. But won’t hurt to be more balanced on the bike 🧘.

At least, I have another metric to watch.

But why? The me it is the ultimate flex if you do show all your training data:

“Here is what I do, good luck with it. I will drop you anyway.”

Reasons for riders to hide their watts

1. Physical capabilities

This matters most for climbers, where raw watts per kilogram (W/kg) often decide race outcomes. If a rider’s power data is public, competitors can analyze their strengths and weaknesses – whether they’re better in a 5-minute VO2 max burst or a 40-minute threshold effort. That kind of insight can shape race tactics

2. Equipment

This one might be the most valid reason – especially relevant in time trials. Publishing TT power data makes it relatively easy to reverse-engineer a rider’s CdA (a measure of aerodynamic drag/how aerodynamic a bike setup is), especially on a flat, straightforward courses. This allows to compare TT setups and determine whether your competitor’s equipment is faster than yours or not. To find out why it is, is the next challenge of course.

3. Training methodology

I’m not sure if “magical” training sessions really exist, but if they do, I guess that’s a reason to hide them. Hiding your training data makes it harder for your competitors to pinpoint how you are training. Is it 40/20s, 3-5min repeats, threshold sessions or zone 2 all day every day? But still, what works for one rider might not work for another. And at the elite level, most performance staff already know what they're doing. It’s unlikely a pro team will change their training programs based on someone’s Strava.

4. (Very) sticky bottles

If one of the thousands of fans along the course hasn’t already caught it on video, power data will give it away for sure. A rider who is flying up a climb doing 0 watts is slightly suspicious. One of the most infamous examples? Arnaud Démare’s miraculous comeback on the Cipressa during Milan-San Remo 2016. He lost contact with the peloton before the Cipressa but somehow made it back before the Poggio, and went on to win.

His Strava file was deleted an hour after the race, only to be re-uploaded later with the Cipressa segment missing. Sure, Arnaud. We believe you pedaled up the whole thing yourself.

5. Doping Suspicion

At last avoiding doping suspicion could be a reason to hide power data. Riders that are putting out power that is perceived to be beyond human limits could raise a debate (rightly or not) around their legitimacy. Ironically, hiding your data can sometimes raise even more suspicion than publishing it.

Some tips to estimate power anyway

There are still a few tricks to estimate how much power your favorite riders (or competitors) are pushing during their rides.

1. Check the leaderboards on KOM segments and see how many watts similar were required for similar segment times (do not forget about weight differences). This works especially well on steeper segments where wind and group drafting on the particular day have little effects.

   

2. Use the calories burned. Many riders hide power but forget to hide calories. Calories burned are 1-on-1 related to power output. Just be sure that the rider used a power meter, otherwise Strava will show a calorie estimate that is not backed by actual power data.

   Some quick math to estimate average power:
   Energy (in joules) = power (in watts) multiplied by time (in seconds):

   1 joule = 0.239 kilocalories, and the human body is about 25% efficient on the bike. Put it all together, and you get this handy formula:

3. Use power calculation tools. If you want to get really nerdy you can use online power calculation tools and input the segment parameters to reverse-engineer the power output that was needed to complete a segment within certain time. Also very useful for your next KOM attack! The tool from climbapedia.org is a nice one. Plugging in the data from la Redoute shows that Pogačar pushed around 8 w/kg for 4min to take the KOM. Not bad.

Who to follow?

Luckily, not all pros hide their data. There are still heroes out there who publish everything they do! Here are a few riders – men and women – who still share their rides including all the metrics:

• Derek Gee (Israel-Premier Tech)

• Fillipo Zana (Team Jayco AlUla)

• Connor Swift (Ineos Grenadiers)

• Paul Magnier (Soudal Quick-Step)

• Warren Barguil (Team Picnic PostNL)

• Puck Pieterse (Fenix Deceuninck)

• Lucinda Brand (Lidl Trek)

• Chloe Dygert (CANYON//SRAM zondacrypto)

  ---

@wattsinside.me Instagram

I am an indoor idiot. I love riding indoors, and I ride indoors A LOT. To give you an impression: over the past year (March 2024–March 2025), I have ridden 1115 hrs and 512 of these were indoors 🤡. That’s nearly 50% of my total time on the bike, so yes, I’m an indoor idiot. However, it is not that I am staring at the wall for 512 hours – I have my coping mechanisms.

1. Podcasts

My favorite entertainment on the bike. It is not 100% indoor-specific as podcasts are also great to listen to during outdoor rides. However, you might not be able to concentrate and listen as well outdoors as you can indoors. My Shokz are great but I can understand close to nothing when riding in a strong headwind. Indoor riding is perfect for podcast multitasking: listen and pedal.

2. Replying to messages

One that is definitely not recommended during your outdoor rides but works perfectly indoors. Replying to your Whatsapp messages, DMs, emails and all the other stuff you don’t have time for or don’t want to do during the day. Small disclaimer: sitting up for too long and typing on your phone might hurt your butt. 🍑

3. Calling people

During your easy and endurance rides, you are perfectly capable of talking. So why not call someone and have a chat? Even better when riding side-to-side in the virtual world. Almost like a real-life cycling date.

4. Intervals

This sounds hard to believe until you try it. 5-minute VO2 Max efforts might feel like they last forever. Nevertheless, time seems to go so much faster when you focus on checking the boxes during an interval session. Give it a shot!

5. Group rides and races

Honestly, I should have put this as #1. This is where the indoor addiction started. Hop into a race or group ride and have fun! Playing video games whilst getting fit. It becomes even better when you combine it with #3. Be like Pogi and make the call yourself: “I’m gone, I’m dead.” Evaluating the race on the radio after the finish is even better and often ends with chatting away extended post-race rides.

6. Streaming

At least you feel less guilty than Netflixing on the couch.

7. Reading

Some people are able to read a book whilst riding. I can’t, but give it a try. It must feel very wholesome to both exercise and read a good book. Normal people are proud if they spend 30 minutes a day doing either of them. Double satisfaction, baby!

8. Bonus: suck it up

Just get it done.

Tip for developers: ENTERTAIN ME

At last a free tip to the indoor cycling app developers: entertain me! There are big differences between online cycling platforms, but generally just riding around remains a bit boring. I demand more stimuli, a higher TikTok-factor when riding around. Some ideas:

• Combine the platform subscription with exclusive content that I can only watch while riding.

• Online dating with sprints: don’t swipe, sprint! Must be a great match if you’re worth 1000W+.

• Let the bots tell me something interesting for once and actually respond to my messages.

• Can I please send people Buzzers like in the MSN days?

• Go full Mario Kart mode: let me throw virtual bananas at other riders!

Not sure if the above ideas will help churn rates, but that’s not my problem.

My Strava

I feel like a bit of a hypocrite. I am writing this article knowing that I am on social media quite a lot and not just Strava. I believe – or at least tell myself – that it is below average. Being completely transparent: as we speak, it is Thursday evening and I checked my screen time for the week. Right on top, my two favorites: Strava and Instagram. Together, they amount to 3 hours. I think it is still a lot over the course of 4 days, but after reading that the average person spends 2 hours and 24 min PER DAY on social media, I am pretty proud.

I am even more proud to see that Strava is on top and not Instagram, Facebook, X or TikTok. Not that I am on any of the latter three, but it comforts me that I am not completely handed over to the big tech companies' algorithms. The only algorithm controlling me is the one deciding whose activity shows up first in my Strava feed. And god, how nice would it be if this would be the same for everyone.

Please Strava, enlighten us

It is – to put it mildly – turbulent times and social media are definitely not making things easier. Billionaires are buying social media platforms and turning them into echo chambers that promote their own good. The people who scream the loudest and with the least nuance get picked up by algorithms and rise to the top of our feeds. The subjects that resonate with us keep popping back up and we get caught in a bubble.

But not on Strava! No, on Strava you need to work for your post. You spend a long time working out – sometimes even hours – during which you have plenty of time to think of what your Strava title will be and what appropriate subtitle belongs to it. No brainless thoughts, unnuanced screaming around on Strava. Strava athletes think before they post. And that’s the difference.

Side note: I am disregarding all the “Afternoon Run”, “Sunny ride with <insert name>” type of titles. I hate those and you will not get my Kudos. Put some work in your Strava title ffs. Thanks.

A call to everyone on social media

Writing a Strava title is a subtle art. I am sure many of my followers will not understand all of mine. Some refer to something only the people on the same ride experienced. Some refer to recurring inside jokes. Some hint at previous rides, so you will only understand if you are a close follower on Strava. Some include a reference to how I feel. Some reveal my take on “things”. But it can all be pretty vague and surely not be understood by everyone (which is on me and not on them!). But that is absolutely fine! Strava is not about screaming the loudest and most controversial stuff to get attention. If I made a few people chuckle while reading my Strava title – one that took me three hours to come up with – then I’m a happy man

And I wish more people used social media that way: post like Strava.

@wattsinside.me Instagram

SHORTCUTS! We love shortcuts.

I read a lot of stuff. Most of it is either irrelevant or simply untrue, some things I've known forever, and a lot falls into the "new but useless" category. But occasionally, I stumble across that perfect match of "didn't know this" and "absolutely want to know this." Recently I came across one of these topics and I want to share it with you. It might not be directly AI-related, but it's definitely tech and data related, and completely in line with that article I wrote about fitness trackers. The value proposition: improve your post exercise recovery and even increase your Vo2 max. Curious? Read on!

“Vague” Nerve Stimulation

So what is the shortcut I came across? It is called vagus nerve stimulation (VNS). Rings a bell? In that case, you know more than I do. Nevertheless, you might still want to hang round as I dug into this a bit deeper. The vagus nerve plays a key role in the autonomic nervous system, particularly in the parasympathetic nervous system.

Taking a quick flight back to what I learned in my biology classes: the autonomic nerve system controls the involuntary body actions (heart rate, organ function, breathing etc.). It has two main branches:

• The parasympathetic branch of the autonomic nerve system calms the body and conserves energy after stress, it is important for recovery.

• Its counterpart, the sympathetic branch, prepares the body for action, stress, or emergencies.

So far for the speed round on biology. The main takeaway here is that the vagus nerve plays an important role in your body's ability to recover from stress. The idea behind vagus nerve stimulation is that it may enhance your body's natural ability to recover.

Stimulation: how so?

The vagus nerve runs from the brainstem down through the neck, chest, and abdomen, branching out to the heart, lungs and digestive organs. There are several ways you can stimulate the vagus nerve:

• Indirect stimulation: makes use of an external device that stimulates the nerve. There are multiple methods, but the most common is attaching a device to the ear.

• Direct vagus nerve stimulation: involves implanting a pulse generator under the skin in the chest and attaching a small, vitamin-sized device directly on the vagus nerve – Yikes!

• Device-free: ‘more everyday’ activities like: meditation, massage, music and cold-water immersion.

  

The implant involves a medical procedure, that is far beyond a shortcut and definitely out of scope of this article. The device-free activities are certainly good practice, but we are looking for a bit ‘more’ here. So let’s dive into the promise of indirect stimulation, with special focus on what it can do for athletes!

The SHORTCUT?!

What can VNS do for athletes? Long story short: it is mostly improved recovery. This study among a group of 90 young individuals showed that 20 min of VNS after a 30min cycling ergometry test helped to decrease fatigue, pain, lactic acid levels and increase parasympathetic HRV activity. So you could use VNS during cool-down or shortly after to ramp up parasympathetic activity – calming heart rate and boosting HRV – which in turn may speed up recovery processes.

This study among a group of 28 individuals found that after 7 days of using VNS Vo2max increased by 3.8% versus no change using a placebo stimulation.

Instant performance gains are unlikely, though. Research shows that a single session of VNS will probably not improve athletic performance. Additionally, this study showed mixed results regarding VNS and HRV. This suggests that the timing, frequency, and exercise load might influence the results.

All in all, VNS is a relatively new technique that has only recently started gaining traction for common use. It won’t replace proper recovery. But science does provide indications that 20 minutes of VNS could mean a faster return to peak performance – and that’s a shortcut worth exploring.

I am explicitly not mentioning any devices that are currently available: evidence is not watertight and differs across different devices. I have never tried it myself. So if triggered, let me know your thoughts and give it a google session yourself!

@wattsinside.me Instagram

Athletes are always looking for something, something to make us healthier, stronger, fitter more energized. 99% of this comes and should come from getting the basics right: eat, sleep, train. Nevertheless, getting a bit of ‘aid’ through supplementing our diet is tempting. But how effective are existing supplements? And can we expect any new supplements to be developed, or maybe even be "AI developed” (OoOOooh!)

Before jumping into this rabbit hole, let’s do some scope setting and definitions. A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill, capsule, tablet, powder, or liquid (Wikipedia). This definition is still extremely wide. Following the categorization by Garthe and Maugnan makes things slightly easier to comprehend:

Most of us will link supplements to the Medical Supplements and Ergogenic groups. To me these are also the most interesting, the others groups seem to be more part of ‘common’ diet. In theory, you can create these in your own kitchen. That is not the case for the medical and ergogenic groups – assuming there is no Breaking Bad Style creatine cooks among you. So let’s focus on these the two groups!

The actual need for supplements

First of all, supplements should be the last thing you focus on in your diet. I love the Athlete’s food pyramid. It shows what is actually important in your diet. Make sure you have a good grip on tier 1 to 4 before losing yourself in supplementation. No multivitamin is going to justify eating crap – excuse me – for the whole day. This does not mean, that supplementation is unimportant. It’s widely accepted that supplementing with vitamin D during winter is beneficial and that vegans or vegetarians should consider adding iron and B12 to their diet.

If you read the IOC consensus statement: dietary supplements and the high-performance athlete (awesome document (!), I really recommend you take a look when you are into this subject), you will find that in addition to vitamin D and iron, especially omega-3 has many positive effects on general health and training adaptation. To a lesser degree vitamin C and zinc can support your immune system. But apart from these three, scientific evidence for other medical supplements is weak.

Looking at the performance-enhancing supplements, there is, of course, caffeine (hello coffee lovers!). Consuming 3–6 mg/kg of caffeine about 1 hour before your race will result in a performance gain of multiple percents. It was even on WADA’s list of banned substances between 1984-2004. In addition to caffeine, creatine, nitrate (beet juice), beta alanine and sodium bicarbonate are proven to be effective. Sodium bicarbonate and nitrate can have a direct positive effect (same day) on your performance, creatine and beta alanine require a loading period of multiple days and weeks respectively. However, none of these will turn Johnny from the local cycling club into Tadej Pogačar. We are talking marginal gains here.

New super supplements?

So there is no supplement that is going to make you fly? One that’s legal, sorry to disappoint, no. At least, not yet, because AI might change this! There are already companies that have specialized in the use of AI to discover new ingredients and optimize supplements for an individual. Nuritas, for example, is actively working with AI to discover new ingredients for their supplements. Their product PeptiStrong (#nospon) is developed with the help of AI. PeptiStrong is a peptide-based food supplement. You can interpret peptides as very tiny, simple proteins. Nuritas developed PeptiStrong by mining trillions of possibilities, identifying novel bioactive peptides to create new ingredients. Clinical studies show that it outperforms animal proteins like whey, significantly improving strength recovery and restoration, reducing fatigue, and positively modulating markers related to muscle homeostasis (see here and here). Interesting stuff!

And this is only the beginning. Some of you might have heard that the 2024 Nobel Prize for Chemistry was awarded for an AI model that predicts protein structures and designs them from scratch. This is a game changer in drug discovery and personalized medicine. It means that we cannot only use AI to sift through huge amounts of existing proteins and ingredients, but we will even be able to build and design new proteins ourselves.

WADA are you reading this?

Although the above might still feel like science fiction, super ingredients are likely to be developed. These developments will likely face resistance, and their application remains debatable. Will AI-designed supplements cross the line between legal supplementation and doping? And what about maintaining a level playing field when access to these AI-designed supplements is dictated by money? I hope WADA is reading this.

@wattsinside.me

You are your best coach. That’s the truth. How did you sleep (don’t ask your Garmin 😉)? Are you tired? Are you feeling great? What’s the weather like at your place? How’s the cold getting along? How’re things at work? Is your baby still crying three times per night? There is only one person who knows the answer to all these questions without asking. You.

Why we want a coach

Yet, many of us seek guidance from a coach to help us determine and adapt our training schedules. And this makes sense. Less experienced athletes turn to a coach to find a starting point – to get an idea of what a training schedule should look like and to understand the basic principles of training. The experienced athlete looks for a coach to find a spokesperson and gain confidence in their training: “Coach put it on the schedule, so it must be the best option.” It can be comforting to stop thinking and just execute.

Stop thinking and just execute. That might be the USP of any coach: the coach does the thinking and the athlete only needs to execute. Doubt is the Achilles' heel of all athletes. Any athlete that tells they never have any doubts is lying. We (unconsciously) doubt everything. Did I train too much, too little? Should I do Vo2 or threshold today? Should I eat more of this or that? Are these new shoes causing my knees to hurt? Doubt costs energy and takes away focus on what matters. That is why we all aspiring athletes like to have a coach.

Trust the process

A coach's main asset is to take away our doubts. Athletes trust their coaches to have the knowledge to compose a plan that will lead to the best result for that particular person. We trust their human intelligence and thus we “trust the process” (cringe) we signed up for. However, artificial intelligence is challenging the USP of the human coach. AI has become such a buzzword that nowadays we put an 'AI' stamp on everything. Companies leverage the general sentiment: “It is AI, so it must be good.”

“It is AI so it must be good”.

This thought helped the rise of AI coaching apps. For 10-20 EUR per month you can get a subscription to an AI coaching platform. In return you get an adaptive training plan and a weekly schedule tailored to you. No thinking, just execute, happy athlete.

AI vs a human coach

Are these AI coaches any good or should you go with the human alternative? Hard to tell. Many AI coaching platforms back their effectiveness with testimonials and data showcasing their customers' great results in training. Although true, this is a distorted image. It is not the schedule or sessions that make the difference. It is purely the athletes adhering and committing to it that makes the difference. An off-the-shelf training plan would yield similar results. However, these are not adaptive, and many athletes fall off the wagon when they miss a session – either losing motivation or overcompensating. It is the adaptability of AI coaching platforms and the trust athletes place in the generated plan that make the difference’. This is, in fact, very powerful and perfectly satisfies our 'don’t-think-just-execute' desires.

However, this is nothing that a real coach cannot do. On the contrary, a good coach can do better. AI is limited to looking at data points to build your schedule. With a human coach you can discuss more in depth: how is your joy in certain training sessions, what capabilities are you missing in races, how is strength training in the morning affecting your evening session etc. AI coaches are not able to tackle this type of in-depth feedback (yet) and adapt training sessions accordingly. However, if you don’t care about this level of discussion, save yourself 150 EUR and go with the AI coach.

The self-coached athlete

At last, and I could write a full article on this topic, the self-coached athlete. The ultimate athlete who is knowledgeable enough to create their own plans, has strong self-awareness and reflection skills, and has intrinsic motivation. (You can guess if I am self-coached? 😁).

Coaching yourself is definitely the cheapest option. Nevertheless, it is also the riskiest one. Speaking from my own experience – and from what I hear from other self-coached athletes – being honest with yourself is the hardest part. Taking a third-person perspective on your own situation is what you should be doing, but rarely do. It is often the case that the athlete is too hard or too soft with himself/herself.

Got a little headache and a stuffy nose? The self-destructive athlete would still go full gas and wreck themselves. In contrast, the self-pity athlete would take a week off the bike to be absolutely sure to fully recover. The best option probably lies somewhere in-between. An (AI) coach can be of great help to find that balance. Nevertheless, self-coached athletes take accountability for their fitness in their own hands. In return they have full freedom to experiment with training and do what they want. Come up with a balanced schedule, then either ignore it or overdo it. Think and don’t execute. Well, at least we had fun.

List of AI coaching apps worth exploring

There are a lot of AI coaching apps available. If you're interested, be sure to check out these:

• JOIN – creates training plans that are fully adaptive. You can change, skip or add workouts and the plan will adapt automatically.

• TrainerRoad – very similar to JOIN. Mostly a matter of personal preference to choose one or another.

• CoachCat – provides you with custom training plans based on your availability and goals, just like JOIN and TrainerRoad. A nice feature is that in CoachCat you can interact with your ‘coach’ via chat, adding a human touch. The company behind CoachCat, FasCat also offers human coaches (for 10x the price).

• Xert – focuses on providing you with advice and insights on your training sessions and workload. Xert Adaptive Training Advisor gives you a workout suggestion that matches your goal and current training load.

The apps above are mainly aimed at cycling. If you have experience with AI training platforms for other sports or additions to the list above, let me know!

@wattsinside.me Instagram

This week OpenAI released Deep Search. Sounds as fancy as any AI tool—but what does it actually do? According to OpenAI: Deep Search is an AI agent that uses reasoning to synthesize large amounts of online information and complete multi-step research tasks for you. In normal human language: an AI chatbot on steroids that generates studies of scientific level, call it a virtual PhD student.

The release of Deep Search triggered me as it makes high-quality research even more widely available than before and made me wonder how this impacts sports. Can teams on a budget leverage AI to artificially pump their science and performance team? Or is it just a handy tool to get a quick fix on your next thesis?

The Battle On Knowing What Works

The key to unlocking higher performance in endurance sports (and sports in general) is to understand what works and what does not work. That applies to the full spectrum of the sport: training, nutrition, equipment, psychology etc. Getting to know what works, or what does not, before competitors find out provides you with an edge.

This fuels an arms race where big teams continuously invest in research to maintain an edge. Over the past years we have seen many examples of how investments in research lifted the bar in sports performance:

• Understanding carbohydrate intake: Team Sky was one of the first teams to crack the code on the glucose-fructose 2:1 strategy.

• Eliud Kipchoge’s Breaking2: Nike’s Vaporfly shoes, an optimized pacing strategy and Maurten’s state-of-the-art nutrition helped Eliud to a Sub-2 Marathon in 2019.

• Visma-Lease a Bike, UAE Team Emirates and Israel-Premier Tech use Carbon Monoxide rebreathers to track and optimize altitude camp adaptations and tune training schedules accordingly.

• UAE Team Emirates are actively working with Ana, described as “our Analog Neural Agent, augments coaching, performance analysis, and communication—helping UAE Team Emirates XRG make more objective decisions while preserving the human connection that drives real progress”. — in short: an AI bot that uses data to optimize training.

• Optimal use of supplements like ketones, bicarb, beta-alanine, caffeine etc.

This is just a small glimpse—there are many, many more examples. Most developments become part of common knowledge, like carbohydrate intake or the availability of carbon running shoes. Nevertheless, for many developments, the teams or individuals that apply them first tend to have a advantage for multiple seasons. Depending on the ‘complexity’ of the innovation competitors tend to take a few years catch up on knowledge and put it into practice.

Big Money vs Big Brains

Innovation costs money. The first (failed) Breaking2 attempt cost Nike 30 million dollars. Especially the development of equipment: shoes, bikes, clothing is expensive. However, acquiring the knowledge in itself, or distinguishing what works from does what not, doesn’t have to be. Especially not when you leverage AI. A lot of research is already out there. It is definitely not always the case that big teams invent the wheel. For example, Jeukendrup et al. already found back in 2004 (!) that you can increase the carbohydrate intake by applying the right glucose to fructose ratio. You don’t necessarily need big money to drive innovation you just need to find the big (AI) brains who did it for you.

AI As Your Complete Sports Science & Performance Team

This is where AI and especially tools like OpenAI’s Deep Search come in. If you are able to identify the hot topics and ask the right questions, AI can help to provide you with high quality, science-backed knowledge and reports. Using the carbohydrate intake example again: imagine asking Deep Search the following question 15 years ago:

"How can endurance athletes optimize carbohydrate intake strategies to prevent glycogen depletion and enhance performance during prolonged competition?"

Your virtual PhD student gets to work, searching for relevant scientific literature available on the internet. With its advanced reasoning capabilities, modern AI can apply fundamental research to your specific context. In a matter of minutes, a comprehensive report is ready. The team performance manager reviews it, and the team applies the insights the next day. This is not science fiction, this is actually possible today.

Smart use of AI might never completely close the knowledge gap between the teams with limited resources and the big money teams, but it can at least reduce it if used well.

Let’s go underdogs!

“How did you sleep?” “Let me check my Garmin app”. That is as stupid as asking if it’s raining and checking your weather app instead of looking outside. And yet, I check my Garmin App every morning.

I have a Garmin watch and I am wearing it 24/7. When I take it off, pale white skin is revealed as a sign of my commitment to collecting all the data day and night.

What Garmin is to me, a Fitbit, Whoop bracelet, Apple Watch, Oura Ring or Polar is to someone else. The wearable fitness tracker market is booming. The annual growth rate in 2018-2022 was 13.5% and it is projected to continue growing with 10%+ in the coming 10 years. Development of Machine Learning and AI algorithms that analyze all the data collected at our wrists have helped to boost the popularity of health and fitness trackers. But what makes us so data-savvy? And are the data points collected by our fitness trackers actually that meaningful?

Data Addicts

I am a training data addict. The first thing I do after completing a ride is check Strava to analyze my own ride and after I can scroll forever and dive into other people's rides. Last week I was on training camp. One of my teammates asked another about her ride, and I called out the exact time and distance before she could even check. Oops.

But I am not alone, most athletes love to dive into the stats of their training. Ideally, we go beyond just tracking workout stats—we want to quantify the factors that influence training and measure how our bodies respond. That is where the 24/7 fitness wearables come in. More data!

Most modern fitness trackers have sensors to track HR, HRV, SpO2, respiration rate and motion. Out of these HR and HRV are most likely the most popular metrics to track our fitness and recovery. SpO2 can be interesting to track your adaptation to altitude and respiration rate is often included in algorithms that compute our stress and recovery levels. Motion trackers are used for many purposes like steps and movement during sleep.

When Things Get Blurry

More data = better, right? It depends. Research tells us that fitness trackers tend to be fairly accurate during rest and low-intensity levels but lose accuracy when intensity and activity level increases (here and here). This is nothing new. I believe we all know wrist-based HR tracking isn’t the most reliable.

When fitness apps unleash their fancy algorithms on medium-quality data, things get interesting. We’re told we’re overtraining, de-training, peaking or doing too little of A and too much of B. Getting these indications right is super hard, even in the theoretical case where all data is complete and 100% correct. But it makes very little sense when the data behind it is blurred or incomplete. I think we have all opened our wearable app at some point and thought: “Huh, de-training?, I have been killing myself on those HIIT sessions”. Well, you might want to check if your wristwatch even got your HR right on those.

Cut The BS

So why am I still checking my Sleep Metrics every morning? Because I cherry-pick the meaningful data points and ignore the rest. Sleep duration, REM, light and deep sleep. They make zero sense, I can be awake, lying still for an hour waiting to fall asleep, and my Garmin thinks I’m in deep sleep. Vice versa, I can sleep like a rock and my Garmin calls it restless. But what I do find valuable is to check my rest HR and HRV. I know these are accurate when measured at rest. Same for training data, focus on key metrics you trust: power, pace and (accurate) HR data. But don’t get fooled by all the fancy blur.

I slept great Garmin, shut up.