Workout after bad night sleep

If you have a hard workout in the program but sleep poorly the night before, what do you do?

I have slept not so good two nights and last night was quite bad (maybe some undereating + worries). I would have today threshold workout (Washington +4) in my schedule. I think I could pass it successfully, but i´m not sure if it is productive because of bad sleep?

My week looks like this

I might swap Pettit and Washington and hope better sleep for next nights…

But my main question is should you do a hard workout if you have slept badly? Or is it just waste of time and you don´t get the benefit/adaptations of workout? Is it better to do just z2 until well rested to attack hard?

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Suffer, fail, indulge in self loathing, question my life choices. Not necessarily in that order


Start the workout, get through the first interval and then decide if you can continue. If not, sub for z2 and move on. I’ve had some really good workouts when I’ve been exhausted and failures when I thought I was fresh and rested.


Was going to state the same thing. Some of my planned workouts after “bad” nights of sleep were pretty hard but went very well, try it to see what happens.

Habitually poor sleeper here. Even when I’ve had what feels like an awful night’s sleep, I usually feel much better after a coffee and some breakfast. It’s never stopped me from hitting a workout.

I’ve learnt there’s no point worrying about it - your body self-regulates itself pretty darn well, and when you really need sleep, it will happen.


For me it depends how I feel, sometimes I surprise myself. Sometimes I find out why I need more sleep. Either way if I mentally can’t deal with a hard workout I swap it for a z2 but most the time I do what people probably shouldn’t. It’s crazy what I can do with 4-5 hours sleep, I usually tell myself in the morning after 4 hours of sleep “Merry F$cking Christmas “ and get after it.

I usually find its not so bad after I’ve started. I’ve a 20mins test tonight though after about 4-5 hours sleep (Lol, Garmin lies, I may have been in bed for 7h40 but I was still awake after 3am) and Ive got an outdoor ride tomorrow so I might try out the ‘Train now’ and pick the middle option (doable).

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Been there and done that… exactly in that order.

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My suggestion would be to stick with the plan but have one back-up exercise, which targets the same zone but with reduced intensity or shorter duration. Usually, it is a minus version of the same workout, but also, it can be another workout from the same group (again, the reduced intensity/duration is the key). So you can start with the prescribed interval, and if at some point you cannot continue, then simply start the new shorter exercise. You get a necessary rest as well while the new workout starts with a low-intensity segment.

Acting this way, you can stick with the zone you have planned to develop on that day. Besides, you do not need to re-shuffle the whole week.

If you are training for a race or event, it is good to know that you can still perform well even if your prep is not perfect. I always start a workout even if I don’t feel up to it and most of the time I make it through. Good two build up your confidence.


I think adaptive training will help so much with this issue. It will give you more options. I see no reason other than your own will not to do the planned workout.

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Same as a few people have already stated here - I would always start my workout and see how I feel during warm up and try an interval. You will know pretty quickly how it is going to go. I’ve had a few recently where I have had a bad night of sleep (I am a terrible sleeper generally), got on the bike and can barely turn the pedals and my HR goes up much quicker than usual. The hard thing is just admitting it is ok to stop and switch to something easier or just give it up for that day.

Sleep is a big challenge for me, and I probably take a similar approach to most of the above posters, with the caveat that I also consider if it’s a one-off or a longer term issue. If it’s just one night of bad sleep I’d probably give the workout a go and adjust if necessary, but in the latter case I think it’s worth questioning whether the workout will actually be productive even if you drag yourself through it. (and related to that, if it might be a symptom of a larger issue. For me sleep is often the first thing to go if my stress levels- training-related or otherwise- start moving into unhelpful territory.)

Unfortunately not the most concrete of answers, but I find “zooming out” and looking at things in a larger context sometimes gives me more clarity than wondering if I “should” do a workout or not.


There’s a study quite recently that showed lack of sleep has hardly any or maybe no detectable performance on race performance that day!

Was very surprising to see, but it’s good news - a lot of people are nervous and don’t sleep well the night before a race.

Personally experience is that I’m hungrier and want to overeat when I haven’t been sleeping well. Less motivated, feel worse when starting the workout, but in terms of actually finishing it’s fine. Actually find that’s what resets me and puts me back on a high for a bit.


The above doesn’t surprise me: last week one of the kids was sick and as a result I had a really bad night. Less than three hours total, and not even in one go. Then got up, dragged myself through a ten hour day at work, only to come home and see Leconte was on the menu… I didn’t feel like starting it and considered going straight for the couch, but eventually thought “I’ll give it a shot and see how far we get”. Ten minutes after starting all fatigue seemed to fade and I nailed the workout. N=1, but confirms what was said above.


I won the Tour of Park City on two hours sleep but failed average workouts after a good night sleep 🤷
One or two nights It might be worth rolling the dice to see if you can complete them unless you wake up feeling absolutely awful obviously. That being said, if a lack of sleep becomes an issue for more than a couple nights it might be wise to do the famous listen to your body thing, and get a little extra rest before you start pushing it. Pushing it while tired as a great way to get sick.


Is there anything people do differently when they have a morning workout and have not slept well?

Sometimes I find that I have an anxious feeling in my chest (hard to describe, though perhaps like heart palpitations) after a poor night’s sleep. Usually this goes after the first interval though, so perhaps it’s just a case of warming up for longer.