Getting the right amount of sleep is of vital importance, as it is believed human performance is highly dependable on the sleep-wake rhythm. But, how much sleep is the right amount and how can sleep quality be optimised?
Science
During the first phase of sleep the body produces low frequency waves which results in a synchronised neuronal activity. Throughout this phase, growth hormone is released which stimulates protein synthesis. Resulting in muscle growth and repair, fat burning and bone building - three key factor contributing to the improvement of athletic performance. Importantly, when athletes lose low waves sleep the growth hormone decreases significantly.
Furthermore, when sleeping the body experiences REM (Rapid Eye Movement) sleep - high frequency waves. Indeed, studies has shown a lack of REM sleep also results in poor memory and motor skills.
Continuously, the immune system is negatively impacted 4-6 hours after a bout of exercise. This is known as immunosuppression and adequate sleep hours can reduce the immune systems decline post training. It seems clear that sleep is important but how much is the right amount?
Recommendations
Typically people need 8 hours sleep per night to maintain good health. However, studies have shown extending sleep can enhance performance in athletes. One study pointed out performance (defined as sprint speed) increased by 4% when sleep was extended to 10 hours per night (subjects were getting between 6-9 hours prior to the study) for a 5-7 week period.
On the other hand if getting the necessary sleep hours (it seems 10 hours is suitable for athletes) is not practical then consider naps during the day. However, naps are split into two categories, short (15-20 minutes) and long (30-60 minutes). A short nap results in poorer long term cognitive function (decision making) but better short term function. Whereas long naps have the opposite effect and is believed to engage the brain in REM sleep.
Additionally, one study found hour long naps were beneficial when supplementing athletes’ night-time sleep. As a consequence it would seem a long term nap is the ideal strategy to ensure better sleep quality and performance.
Moveover, to further increase sleep quality consider de-stimulating the brain 45-60 minutes before going to bed. During this period avoid electronics and social media. Completing flexibility work at night is also beneficial as the muscles are more relaxed. Lastly, wake up and go to sleep at the same time every day. As this increasing the efficiency of the body's sleep-wake cycle - including hormone production.
References:
Mah, C., Mah, K., Kezirian, E. and Dement, W. (2011). The Effects of Sleep Extension on the Athletic Performance of Collegiate Basketball Players. Sleep, 34(7), pp.943-950.
Bird, S. (2013). Sleep, Recovery, and Athletic Performance. Strength and Conditioning Journal, 35(5), pp.43-47.
Lastella, M., Lovell, G. and Sargent, C. (2012). Athletes' precompetitive sleep behaviour and its relationship with subsequent precompetitive mood and performance. European Journal of Sport Science, 14(sup1), pp.S123-S130.
Reilly, T. and Edwards, B. (2007). Altered sleep–wake cycles and physical performance in athletes. Physiology & Behavior, 90(2-3), pp.274-284.
Romyn, G., Lastella, M., Miller, D., Versey, N., Roach, G. and Sargent, C. (2018). Daytime naps can be used to supplement night-time sleep in athletes. Chronobiology International, 35(6), pp.865-868.
