Strength and endurance training should be prioritized after a bad night’s sleep

After a bad night’s sleep, nothing feels right. The mind is confused and the muscles are weak. Often the last thing you want to do is sweat. You may wonder what kind of workout you should do and whether it’s best to put it off until you don’t feel so groggy.

Recent work by researchers in Australia suggests that low-sleep exercisers can get the most out of a workout if they do it early in the day and focus on strength and endurance rather than complex skills.

The meta-analysis, published in the November issue of Sports Medicine, is the latest in a series of studies examining the link between sleep and athletic performance.

“The key factor is, ‘What kind of sleep loss did you have?’ And then: ‘When are you going to train and what are you going to train?'” said Jonathan Craven, a graduate student at Griffith University in Queensland and one of the authors of the paper.

The type of training makes a difference

The meta-analysis, which combined data from 77 studies, examined the effect of a single night of reduced sleep — that is, less than six hours — on strength, endurance and athletic ability the next day.

As with previous studies, the Australian team found that poor sleep impairs most aspects of athletic performance, such as speed, power, stamina, and complex skills like hitting a tennis ball or cutting a volleyball.

Scientists put each practitioner’s performance on a percentage scale. They found that after poor sleep, complex skills decreased by up to 23%, while strength and endurance suffered losses of up to 5% and 8%, compared to exercises performed after a full night’s sleep.

In other words, after a bad night’s sleep, some people’s ability to hit the target in an archery session was much more affected than others’ ability to run at a certain speed or lift a certain weight.

“The longer an activity, or the more the activity demands of your brain, the more likely you are to have a negative effect of sleep deprivation,” said Shona Halson, a researcher at the Australian Catholic University in Brisbane who studies the effect of lack of sleep. sleep in athletes and did not participate in the study.

“If you’re trying to do a 100-meter run and you’re not sleeping, you probably won’t be affected as much as someone who runs a marathon or plays tennis.”

time is everything

The researchers found that exercising earlier in the day, right after waking up, helped to minimize the effects of sleep loss, and the negative effects slowly increased as the day wore on.

“If you’re sleepless and you have a choice, it’s probably best to train in the morning,” Halson said.

For example, athletes’ performance in complex skills dropped by 14% when training was done in the morning after a bad night’s sleep, and by 23% at night.

Those who did weight training performed 2% below normal during a morning workout, while those who waited until late at night had their performance reduced by 5%.

The study showed that this effect was strongest among exercisers who lost sleep from waking up too early rather than going to bed too late. The researchers suggest that athletes traveling to competitions may be better off traveling at night and sleeping nearby, rather than prioritizing an early rise.

The reason for this reduced performance is related to the body’s circadian rhythm, which naturally makes people feel more alert when it’s bright outside and tired when it’s dark. The body releases adrenaline — “its endogenous energy drink” — in response to morning light, said Virend Somers, a cardiologist who studies the effect of sleep loss at the Mayo Clinic.

And adenosine, the chemical that creates the feeling of drowsiness, tends to be lowest in the body right after waking up, increasing as the day goes on, Halson said — the more adenosine in your body, the more tired you feel.

She emphasized that a bad night’s sleep doesn’t mean you should cancel your workout. If you can’t work out in the morning, maybe skip the tennis match or basketball game and focus on strength and endurance exercises.

“People often get bad nights sleep,” she said. “A bad day of training doesn’t make you a bad athlete, and that bad night’s sleep doesn’t make you a bad sleeper. It’s the consistency of what you do over time that matters.”

Translated by Luiz Roberto M. Gonçalves