Daytime naps and their effect on workouts

Author: Mikhail Ziborov - author of the site makefitness.pro.
2022-02-21

I once heard from more experienced trainers that they themselves nap and recommend their trainees to sleep during the day. And then it started! What advantages does a daytime nap provide? Is it only beneficial for health, or can it improve athletic performance? And how much should one sleep during the day? In short, we are tirelessly digging up new and interesting information (this and other) that we are eager to share.

Daytime sleep (afternoon nap, napping) is a short sleep during lunchtime and after lunch. For example, in China, schools practice short naps right at their desks. As the Chinese say, this improves children's learning productivity.

In South American and Mediterranean countries, this is called siesta. It turns out that daytime sleep offers both physical and cognitive benefits.

Daytime sleep and the nervous system (cognitive functions)

Various quality studies unanimously agree that daytime sleep enhances cognitive functions of the brain: reaction speed, attention (vigilance), memory (for example, see this study).

Simply put, due to napping during the day, the nervous system relaxes. This can be useful for both people engaged in mental labor and athletes. After all, the nervous system is responsible for muscle contractions, and the more rested it is, the more productive the training will be.

And I haven't even mentioned the improvement in heart health (researchers noted significantly fewer cardiovascular diseases among those who napped during the day compared to those who did not).

Daytime sleep and strength/endurance

If you are partially sleep-deprived (averaging 6.5 hours of sleep at night), a daytime nap shows clear improvements in strength and endurance (see studies 1, 2, 3).

In subjects who were sleep-deprived, sprint time and jump height, i.e., explosive strength and endurance improved. However, grip strength did not change. The studies tell us: if you're partially sleep-deprived at night, a daytime nap will help you have a more productive training session that same day.

Considering that many of us do not get enough sleep but lead active lifestyles (train or have increased day-to-day activity), a short nap will help you stay more alert and productive.

If you sleep enough (averaging 7.5 hours), performance still improves, just as with sleep deprivation (study).

By the way, daytime sleep even improves qualities like accuracy (agility) but only if you were sleep-deprived at night (study).

Daytime sleep and recovery/muscle mass

Notably, daytime sleep concerning recovery has been studied from two perspectives – before physical activity (study) and after it (study). In either case, sleep accelerated recovery.

Sleep is when recovery reactions accelerate compared to waking time, which allows the body to adapt to loads, grow, and become stronger. Daytime sleep can help achieve your athletic goals a little faster: it reduces muscle soreness (creatine), improves overall well-being, and speeds up muscle gain.

Let me remind you that the main key to muscle growth is a training program and a proper diet. Everything else (supplements, training techniques, other tricks) are just additions that provide advantages over those who do not use them.

How much sleep is needed during the day, and what hours are best?

In studies, sleep for 5 minutes was found to be ineffective for improving anything.
However, starting from 7 minutes, improvements began to increase. Thus, a short nap (20-30 minutes) is preferable for individuals wanting to enhance cognitive functions (memory, attention, etc.). The thing is, this kind of sleep does not cause sleep inertia – the various declines in both mental and physical performance (see more below). But 20-30 minutes of sleep is much better than having none at all.

On the other hand, a long nap (35-90 minutes) offers greater advantages for athletes wishing to train more productively, although it does come with sleep inertia right after waking.

A short nap (7-20-30 minutes) improves performance by an average of 125 minutes (i.e., the effects of daytime sleep last this long). A long nap (35-90 minutes) improves performance by 155 minutes.

In summary, for enhancing cognitive functions or physical performance without sleep inertia, a period of 7 to 30 minutes is suitable. For longer improvements in cognitive functions and physical performance, but with sleep inertia, sleep ranging from 30 to 90 minutes is recommended (see studies 1 and 2).

The best time for a daytime nap is between 1:00 PM and 4:00 PM. After waking, if the nap lasted longer than 30 minutes, do not engage in mental or physical work immediately (you will experience sleep inertia when your performance is diminished). After waking from a longer nap, give yourself 30 minutes to recover before proceeding to training or mental work (study).

Sleep inertia

Sleep inertia is the decline in both cognitive and physical qualities immediately after waking. Simply put, it's the grogginess you feel, even though you’ve started to awaken. You shouldn’t start training or working your brain during this so-called sleep inertia.

For information on what your nighttime sleep should be like, how much sleep is best, see this article.