One of the questions I get a fair amount now that sleep is trendy is:

“What happens if I get only one night of very low sleep?”

Bella the corgi is ready for bed with PJs on.

It turns out that my buddy (and one of the experts featured in the Flex Diet Cert), Dr Hunter Waldman posted a great study (1) about this very thing!

“Pretty sweet study on sleep restriction.

Couple of take-aways:

  1.  More sleep (~8-9 h) = optimal performance.
  2. One night of sleep restriction (<5 h) might not impact performance much the next day, but multiple nights significantly reduces performance.
  3. Perceived effort remains the same regardless of sleep duration, BUT power output decreases with less sleep. You think you are working just as hard with 5 v 8-hours of sleep, but physically, power output is less.
  4. “Fitness levels seems to play a role exactly how much you’ll be impacted but regardless, if you have a competition coming up, getting at least 8-h sleep for 3-4 nights prior is optimal.”- Dr Hunter Waldman

Want to know a very cool take away and something I have personally noticed to?  If I get less sleep for a single night, I am normally pretty good, but my RPE (how hard you feel you are working) definitely goes up.

For those who closely reviewed this study, you will notice that this was for endurance exercise.

I’ve found that for strength training, you can buffer one night of poor sleep; however, you will need to extend your rest periods to keep the quality of work high.

Endurance training is primarily aerobic metabolism and the rest periods between lifting sets is based on aerobic metabolism too; thus, extending the rest periods allows more time for this struggling aerobic system to replace those ATP (energy stores) before you hit the iron on the next set.

In English – if you are lifting on a poor night’s sleep, extend your rest periods between sets.

If you want to put on your propeller-hat and go chin first down the nerd chute even further, I did 5 short podcasts on sleep, check them out below on episodes 6 -10 at

>> Not Another Fitness Podcast <<  episodes 6 -10 on sleep

Don’t worry, they are pretty short, and I keep the nerd speak to a minimum.

Rock on!
Dr Mike

Nerd Fuel

1) Roberts SSH, et al. “Extended Sleep Maintains Endurance Performance Better than Normal or Restricted Sleep.”  Med Sci Sports Exerc. 2019.  URL