Cyclists' hearts: can you be so fit that you die?

Cyclists' hearts: can you be so fit that you die?

can you be so fit that you die it's not really a question the person who keeps me up at night but I did start to wonder why over the last few decades have so many cyclists died mysteriously in their sleep like most men hurtling towards middle-age I bought myself a road bike and some ridiculous lycra and on a beautiful London sunny day like today I like to pretend I'm in that Tour de France however as soon as I hit a hill I remember that I'm not Marco Pantani the late Marco Pantani is regarded as one of the greatest hill climbers in cycling history he pushed his body to such extremes that his resting heart rate was only 34 beats per minute when he slept it could drop so low that his life was actually in danger meaning that he had to wake up and ride on a stationary bicycle to get his heart rate up during the day he lived to ride but at night he rode to stay alive assuming you're not watching this YouTube video whilst a swimming 800 meters or B being Mo Farah your cardiac output at rest ie the volume of blood your heart pumps in a minute will be around five liters and your heart will weigh something like 300 grams however if you're an Etruscan shrew your heart weighs only twenty milligrams and beats over 1,500 times a minute conversely an elephant's heart weighs a whopping 15 to 20 kilograms and beats 30 times a minute in fact most mammals have a fairly linear inverse relationship between body mass and heart rate the bigger the heart the slower the rate yet miguel indurain another legendary cyclist in fact a five-time Tour de France winner famously had a resting heart rate even lower than Pantani's at 26 beats per minute and despite speculation at the time I can definitively confirm he was human so how on earth did these men have heart rates comparable to that of an elephants let's go back to you and your resting cardiac output of 5 liters a minute you could probably get this up to 20 liters a minute at peak exercise again assuming you're fairly average a fit amateur cyclists might get 225 litres a minute in Duran could exceed 50 liters a minute figures like this tell you immediately that these athletes are freaks they possess amongst the most extreme physiology you will find in a member of our species their metabolism is more efficient and their hearts are literally bigger than normal let's contrast this with someone very far from extraordinary me my Fitbit tells me that my resting heart rate is 48 beats per minute when I sleep as is normal my heart rate drops I found my heart rate appears to drop below 40 at night now I'm clearly far less fit than these cyclists yet I don't need to wake up at night to speed my heart up so why did pant Annie as some of you may have guessed the one major factor I haven't mentioned so far is that both these men were racing in the 1990s when performance-enhancing drugs permeated the sport now performance-enhancing drugs are a discussion for another day and another video so before the lawyers get involved I should say that neither of these athletes tested positive during their careers but their hematocrit s' were very high the hematocrit is the proportion of your blood that's a made up of red cells the red cells job is to carry oxygen from the lungs to the body including your muscles a high hematocrit can be achieved by taking excess amounts of a naturally occurring hormone erythropoietin or EPO yes or no was one of those banned substances EPO yes as muscles work harder they need more oxygen the more oxygen you can deliver the more work the muscles can do we can actually measure this in an exercise lab the vo2 max is the maximum oxygen consumption someone can achieve I had mine measured in Cambridge a few years ago and got a barely above average vo2 max of 48 vo2 max measurements are commonly used in healthcare not for the very fit but for patients whose hearts aren't working well to give us an idea of when to intervene I used to perform this test in patients referred for consideration for a heart transplant to give you an idea of scale a patient would qualify for a transplant if their vo2 max fell below 14 I'm here somewhere in the middle and pant Annie and in Duran are way up here with vo2 max readings in excess of 100 in part because they had so many red cells to carry that oxygen but all these red cells come at a price the combination of an almost pathological slow heart rate and noticeably more viscous blood meant that when the cyclists bodily functions slowed during sleep they were literally risking death an excerpt from Matt Randall's biography the death of Marco Pantani the gel-like blood is great for high performance but totally unsuited to rest and at night when the heartbeat slows its sheer density becomes a liability it is as if the fleet's of heavy traffic rumbling down the motorway with fuel for the furnaces suddenly slowed to a crawl in a potentially catastrophic traffic snarl up the athlete has to set his heart rate monitor to beep whenever his pulse drops below a certain level say 35 beats per minute when it sounds he has to wake up an exercise to coax his straining heart into action between 1987 and 1992 when EPO was new on the scene and doctors weren't experienced at doping athletes safely 20 young Belgian and Dutch cyclists and seven Swedish endurance athletes died mysteriously in their sleep mortality has improved but cyclists have continued to die in their sleep as recently as 2009 or even November 2017 Pan Tony himself retired under a cloud of performance-enhancing drug allegations and withdrew from society he was tragically found dead in 2004 and his post-mortem revealed heart failure and cocaine toxicity I don't wish to speculate on the circumstances of his death but cocaine can cause heart attacks even in fit people by causing the artery supplying the heart to spasm but also by affecting the stickiness of the blood making it more likely to clot just like a high hematocrit he was 35 years old elite athletes hearts can do strange things watch out for future videos where I'll discuss some of these and sometimes extreme fitness comes with its own problems but it's highly unlikely to be fatal unless you throw drugs into the mix so no you can't be so fit that you die don't forget to check the description below for some further reading this is my second video I hope you enjoyed it if you did please give it a thumbs up but to tell the great YouTube algorithm in the sky if you didn't I think I can do about that now it's kind of weird that you watched at the end you should probably subscribe anyway just to tabs on how bad my future videos will be if you want me to stop making videos altogether then I will challenge you to a cycling road race but no Hills [Applause]


  1. In my profession where high fitness is common and part of the job for many (not necessarily elite fitness, but high-normal) I have seen many colleagues die young. My understanding is that cholesterol and arteriosclerosis can exist undetected in fit people, and the problem is that fit people can compensate for the reduced circulation for much longer than less fit people so that flow can be reduced to a much higher degree before detection, or perception bu the person. At that point even a relatively small or minor clot or embolism can result in unexpected total blockage, resulting in death. Everyone else is left saying, “wow, and he was is such good shape…”

  2. Sorry but where did you get that Pantani and Indurain had VO2max over 100? That’s well above the world record, which is 96 ml/kg/min. Are you using a different unit of measure?

  3. Your content is awesome. Intelligent, well supported, interesting, useful, and super funny and entertaining! Please keep it up!

  4. Man, I've been thinking out this for awhile. I've come across a few cyclists with MIA's in Europe and in emergency rooms in the US who were quite fit. I also switched from running and other sports to cycling and noticed that my heart feels like it "flutters" from time to time. When I rowed crew I felt the same occasional feeling. I've never been able to capture it with data, but I hypothesize that in cycling and rowing relative to say, running, I'm using a few primary muscle groups instead of a whole body musculoskeletal system. The body could be getting mixed signals concerning carbonic acid concentrations, hormone levels, and other key metrics that feedback into the regulation system. This is just a theory, but I'm curious if anyone else has had one of these experiences. Thanks for bringing this topic to light.

  5. Good stuff. Could you do a video around the heart condition which nearly killed footballer Fabrice Muamba back in 2012. I understand that is to do with very strong heart muscles causing an inadvertent throttling of one of the input/output veins and arteries.

  6. I've heard that too much endurance exercise strains the heart and causing scarring which can be a danger.

  7. because they want to live like they are a pro rider and they use drugs . same as a local gym rat you aren't going to be arnold but they pump the roids in themselves like they are and they die too.

  8. Great video, your own heart rate is athletically low enough, at 54, on an undulating hilly course of only 2.5km is absolutely brilliant to keep the heart in shape, the only problem is when i get fitter, the Achilles starts to ache, best advice I've seen on line is to hold the Achilles stretch for minimum of 2 min. Looking forward to ur videos. Is there a diy method to determine vo2 max approximation, would be handy.

  9. It's not just cyclists. You can overdo an exercise regime. I considered myself very fit as did my doctor but all that running, football, cycling, swimming, rugby, volleyball et al absolutely ruined my joints, plus my cervical and lumbar spine which resulted in a shortened career as a firefighter and early retirement. I still cycle but now it's an ebike as part of my rehabilitation for the inevitable heart attack which resulted from my enforced sedintary life (relatively) and sleep apnea. I believe my sleep apnea was due, also, to my very low heart beats per minute; normal mid 40's and rest high 30's. I have never, ever used any form of non-prescription or recreational drugs. Looking back I really wish I hadn't been so active and I would have completed my career choice and been far better off physically than I am now. Some of my competitive sporting friends have long gone leaving those who kept relatively fit without going mad are enjoying pain free and mobile retirements. Hindsight is a wonderful thing.

  10. I had a resting heart rate around 35 bpm for a bit. My personal trainer was amazed, because I was a fat fuck who couldn't do shit, but turns out it was a thyroid disorder. Still, for a short time, someone thought I was as fit as an elite athlete and that's all that matters. Nice to know that, with fun weekends mixed in, I could have died in my sleep.

  11. Cocaine can also mess with the electrical conduction of the heart, because it's promiscuous and binds to the ion channels in heart cells.

  12. Doping is the reason why they died of heart attacks. Epo thickened the blood which is why they had too wake up at night to speed up there heartbeats. The cheating doping cunts.

  13. So he was fine until he was removed from cycling. Then…. he Died like a rockstar.
    Your clickbait title and your narrative don’t match the facts

  14. I was actually a tad worried, since my heart rate drops to 40 during sleep, but this reassured me a bit.

  15. Isn't 48 bpm actually a VERY good resting heart rate? I wouldn't call that average at all. I thought the average for "norms" is around 60 – 100 bpm at rest. I used to run 8 miles every other day and my heart rate at rest was around 45/50ish.

  16. I used to have a VO2 max over 75. I dread to think how low it is now due to not being able to exercise due to skeletal damage.

  17. I am an official for USAC. Most people assume the reason we ban these drugs is because of the performance-enhancing properties. We believe some have an unfair advantage over others. There is an aspect of that, but a big part of it is the harm done to the athlete. Being really great at a sport should not cost you healthy relationships, future well being, and especially your life. We must always remember no matter how high we go in a sport it is a game. We are meant to be having fun.

  18. Could you perhaps mention how high intensity exercise could suppress your immune system due to the production of less white blood cells. Making you more susceptible to infections and illnesses.

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