I've been ramping up my training sessions (cycling) for the last few weeks to get in shape for a commitment I made. Getting ready for an ultra-endurance event in 2 years.

I train about 4-5 times a week, during weekdays I tend to focus on recovery rides, interval training and build up my general endurance. During the weekend I ride about 80-130 miles, two days in a row. (If possible) These long rides are to build my mental game, to get used to being in the saddle for long stretches of time and to learn to keep going while being tired.

So far this is doing wonders for my condition, pacing and mental endurance. But one thing I am worried about is getting enough sleep. Naturally, I sleep about 5 - 6 hours a day, I wake up without an alarm. Waking up feeling rested. Since I started training more frequent I see my sleep drop to 4 - 5 hours while not waking up tired. This is extremely short, even for me.

From what I've been told. Sleep is essential for focus, productivity, muscular and skeletal system recovery, memory, energy levels, mood and a lot of others. Although I feel great a.t.m. Should sleeping this little be worrying? What would be causing this drop in sleep?

  • What could be happening is that you get a higher quality of sleep because you work out and your body has more desire for deep (stage 3) sleep, which means you would need less quantity of sleep. – MJB Mar 22 '19 at 14:07
  • Just as a side note, many people who bike are not aware that this exercise form does not improve bone density. In fact, intense cycling over the course of years will reduce bone density. I find that many people who love cycling are in denial about this medical fact. I was wondering if you were aware of it? The research on this topic is extensive. Please see sciencedirect.com/science/article/pii/S2255502116000328 Sorry to be a Debbie Downer. – Chris Mar 24 '19 at 20:01
  • @Chris I was not aware of that. I've been riding BMX (freestyle and race) for over 15 years and road cycling for about 6 years. Riding BMX has caused multiple fractures over time. Mostly because of bad crashes or heavy impacts. I will read more into this. – Odyssee Mar 25 '19 at 8:27
  • 1
    BMX cycling is different from road cycling because people don't generally BMX continuously for hours (as far I know) and because there is more impact in BMX. So my guess is that BMX is fine for your bones - except for when you fall, of course. Since BMX is a niche sport, I doubt there is any research on it. The research is done with road cyclists. – Chris Mar 25 '19 at 16:59

My guess is that something is not right. When I do an intense workout (lifting weights), I sleep more that night, not less. That is one of the benefits of exercise. If you search the internet for "overtraining", you will find that disturbed sleep is one sign of overtraining. Here is a reference. On the other hand, you say you wake up rested. I don't think that is typical over overtraining. It seems like you have two contradictory symptoms. Maybe you need to keep going with what you are doing until you figure out what is happening.


Unfortunately, as is often the case in heath sciences there is never an exact answer, as such an answer would require a rather large collection of information about the individual which is functional nonpragmatic. However, that doesn't mean there aren't answers to different questions that can be asked. One such question could be

If I was getting too little sleep, how would that affect me mentally or physically?

In a rather in-depth report published in Clinical Review by M. Chennaoui et al. (found here), they looked into the various links weekly exercise had on sleep and how sleep would then affect different aspects of their physical health. Much of what was reported was that exercise (less intense but similar to that of yours) seemed to increased total sleep time, which is something that you seem to be in contradiction with. However, they also assert that acute sleep loss will affect your metabolism and inflammation which in turn affect things like alertness, mood, heat tolerance, and some other proposed connections. This can all be overwhelming but the point is to ask yourself if the change in you average night sleep have been affecting aspects of your daily life. There's a lot of unknown in this area of science and still room for outliers in typical physical behavior. It could be the case that your conditions you're putting your body through are such that 4-5 hours of healthy sleep are optimizing. I'd highly recommend combing through this research and seeing if it answers any of your own questions. Also if the concern is high enough always consider consulting a physician or a physical therapist.


A thought--an increase in cortisol decreases sleep. If you feel well rested, your cortisol could be high in the morning or some other reason.. but working out/stress/ going to work increase cortisol. Most people need up to 2 extra hours of sleep when working out to recover, so if anything you should be at least sleeping 8 hours. I sleep 10 on training days.

You could also have a sleep disorder or some type of sleep insomnia

This is a medical question in my opinion and warrants a visit to the Doctor as it is not healthy to sleep so little and will cause you to be sleep deprived

  • Thanks for the answer. Now, over a year later I'm still training long and hard. My sleep went back to normal, my average time spent sleeping is actually higher this year than what I'm used to. In the period my sleep was affected I never felt really tired or did it affect my mental and physical abilities. – Odyssee Sep 25 '20 at 13:23

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