For several years, it was believed that sleep or nap was of primary importance in the management of brain function. A new milestone has reached in the science of sleep with the discovery of its impact on several physiological factors. Many studies have reported the link between sleep and exercise performance. Lack of sleep or rest seems to impair physical performance especially in circuits of long durations. Post-workout sleep or nap helps in the recovery of skeletal muscles.1 This article mainly focuses on the relationship of the sleep or nap after workout, advantages and disadvantages of post-workout sleep, duration and other factors influencing the post-workout nap/sleep.
Hormones, Exercise and Sleep- A circadian rhythm
Exercise activates the physiological pathways of hormonal system. Two of the main hormones often studied in relation to physical activity are Cortisol and Testosterone. Cortisol, a steroid hormone, plays central role in the physiological and behavioral response to physical activity and regulate metabolic functions of the immune system. Testosterone is also a steroid hormone associated with physiological response to exercise and contribute to muscular hypertrophy during resistance training.2
The balance between the anabolic (testosterone) and catabolic (cortisol) hormones are essential for the muscle adaptation and growth. Testosterone and cortisol work according to circadian rhythm. Lack of sleep or proper rest increases the secretion of cortisol and changes the pattern of rhythmic secretion of testosterone that can affect the anabolic and catabolic balance.2
Leptin and ghrelin are two other hormones important for regulation of appetite. The duration, quality and timing of sleep decides their levels in body. Sleep-wake cycle is also largely responsible for insulin secretion and glucose tolerance. It is therefore proposed that two time keeping central nervous system mechanisms i.e. circadian rhythmicity and sleep-wake homeostasis regulate the propensity and architecture of sleep. Circadian rhythmicity includes basic effects of biological time, regardless of sleep or wake state and sleep-wake homeostasis is controlled by duration of prior wakefulness, regardless of time of the day.3
Is it ok to nap/sleep after workout?
Historically, no daytime behavior other than exercise has been closely associated to sleep. Most of the epidemiologic studies have reported a positive association between exercise and better sleep patterns. After workout or any form of physical activity or sports activity, sleep serves as a source of energy conservation function, a body tissue restitution function, and a temperature down regulation function. Taking a nap or sleep after workout helps to rebuild the muscle strength. A short nap or sleep helps in making the health better, reduces stress and increases the willingness to exercise.4,5
Advantages and disadvantages of sleep or nap shortly after workout
Advantages of taking a nap:
Recovery: taking a nap after workout helps in the recovery of muscles. While resting or sleeping, there is a release of growth hormone from pituitary, which helps in muscle growth, wear and tear repair and athletic performance.
Improved sleep debt: with sleep deprivation, muscle recovery is slowed down. It also hinders the cognitive function and weakens the immune system, contributing to poor performance during workout or sports activity. Taking a nap helps in covering the sleep debt and faster recovery.
Physical fatigue: sleepiness or drowsiness feeling after exercise indicates muscle fatigue. Napping or sleeping after physical activity encourages muscle recovery and decreases fatigue. Thus, it makes the person ready for other necessary commitments during the day.
Increased mental alertness: taking a short-nap post workout gives a boost of mental energy. It also reduces fatigue and therefore person is able to carry out the routine activities in a better way.
Disadvantages of taking a nap:
Sleep quality: exercise increases the temperature of body and the release of endorphins. These changes from exercise manage to keep your brain and body vigilant. So, even if one is feeling tired and wants to sleep, it is difficult to get quality sleep.
Increased disorientation: if the nap/sleep time is longer than recommended, post workout nap may convert into deeper stages of sleep. This causes the sense of confusion and disorientation on waking up. This stage is known as sleep inertia also named as Hicham’s syndrome. The person wakes up in a physiological state of disabled sensory-motor and cognitive behavior. This can last up to 30 minutes.
Disruption in night time sleep: napping helps in recovery and cover the sleep debt but it can also negatively affect the night sleep patterns.
Ideal timings and duration for a quick nap
Nap/sleep after workout has been documented as a behavioral measure to alleviate the loss of sleep. In particular, there are two ideal time durations for a nap. Previous studies have suggested that nap duration of less than 20 minutes is preferential, as it reduces the likelihood of waking up during a slow- wave sleep, thereby increasing sleep inertia. Alternatively, 90 minutes is also considered optimal as it allows to complete the sleep cycle (REM and NREM) and helps in reducing effects of sleep inertia.2
Other factors influencing the post-workout nap/sleep
Not keeping a consistent sleep schedule: It is always better to practice sleep with a consistent schedule. Healthy sleep can be trained and improved by following regular routine and timings. 8
Duration of nap/sleep: as discussed earlier duration or nap timings are very important factors to make up for the sleep debt. Avoid taking nap after 4pm as it may disturb the night-time sleep cycle. 2 The napping benefits are best achieved by training the body and mind to wake up after a short nap.9
Time to slowly swift into sleep: Sleep hygiene practices should be followed properly. To prepare body to swift into sleep, switch off all the electronic devices like television or phone. Dimming lights are also some of the methods to slowly swift into sleep. 8
Keep the conditions optimized: keep the room temperature optimum, such as too low or too high air temperatures, or relative humidity may disturb sleep. Sleep is also seasonally dependent, according to summer or winter or spring.10
Reducing mental fatigue: Sleep for muscle recovery after exercise is not useful if mental fatigue is not taken care of. Reducing mental fatigue is just as important for healthy sleep. External stressors in your life should also be reduced. 8
To conclude, it is common to get tired after a workout or physical activity. Body needs to recover from the muscle fatigue and replenish the loss of energy. Post-exercise sleep or nap speeds up muscle recovery and energy. It is important to limit the duration of nap to avoid confusion of mind and to avoid disruption in night-time sleep cycle. We should keep in mind that naps are not a substitute for night-time sleep. Hence, it is always better to practice post workout nap/sleep with a consistent schedule.
- Dáttilo M, Antunes HKM, Galbes NMN, et al. Effects of Sleep Deprivation on Acute Skeletal Muscle Recovery after Exercise. Med Sci Sports Exerc. 2020;52(2):507-514
- O’Donnell S, Beaven CM, Driller MW. From pillow to podium: a review on understanding sleep for elite athletes. Nat Sci Sleep. 2018; 10:243-253.
- Leproult R, Van Cauter E. Role of sleep and sleep loss in hormonal release and metabolism. Endocr Dev. 2010; 17:11-21.
- Youngstedt SD. Effects of exercise on sleep. Clin Sports Med. 2005;24(2):355-xi.
- Driver HS, Taylor SR. Exercise and sleep. Sleep Med Rev. 2000;4(4):387-402.
- Milner CE, Cote KA. Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping. J Sleep Res. 2009;18(2):272-281.
- Peake JM, Neubauer O, Walsh NP, Simpson RJ. Recovery of the immune system after exercise. J Appl Physio. 2017;122(5):1077-1087.
- Vitale KC, Owens R, Hopkins SR, Malhotra A. Sleep Hygiene for Optimizing Recovery in Athletes: Review and Recommendations. Int J Sports Med. 2019;40(8):535-543.
- Dhand R, Sohal H. Good sleep, bad sleep! The role of daytime naps in healthy adults. Curr Opin Pulm Med. 2006;12(6):379-382.
- Kim M, Chun C and Han J. A Study on Bedroom Environment and Sleep Quality in Indoor and Built Environment. 2010; 19(1):123–128.