Sleep has important functions for learning, memory, and cognition. Studies have suggested that almost all human physiological processes begin at the onset of sleep. A person’s sleep history has an impact on daytime functioning. Restricting sleep to less than 6 h per night for 4 or more consecutive nights has been shown to impair cognitive performance and mood, glucose metabolism, appetite regulation, and immune function. This type of evidence shows that everyone should have 8 hour of sleep per night to prevent neurobehavioral decreases.

Sleep Deprivation

There have been a few studies that have examined the effects of sleep deprivation on athletic performance. Recent researched measured cycling maximal power, peak power and mean power pre and post 24 and 36 h of sleep deprivation. Up to 24 h of waking, anaerobic power variables were not affected, but were impaired after 36 h without sleep (Halson 2014).

Studies have examined the effects of 24 h of sleep deprivation in nine US college-level weightlifters. There were no differences in any of the performance tasks (snatch, clean and jerk, front squat, and total volume load and training intensity) following 24 h of sleep deprivation when compared with no sleep deprivation. However, mood state, as assessed by the profile of mood states, was significantly altered, with confusion, vigor, fatigue and total mood disturbance all negatively affected by sleep deprivation (Halson 2014).

Partial Sleep Deprivation

Few studies have examined the effect of partial sleep deprivation on athletic performance. The effect of 2.5 h of sleep deprivation per night over 4 nights was measured in eight swimmers. No effect of sleep loss was observed when examining back and grip strength, lung function, or swimming performance. However, mood state was significantly altered with increases in depression, tension, confusion, fatigue, and anger, and decreases in vigor (Halson 2014). There was a negative effect of sleep loss on maximal bench press, leg press, and dead lifts, but not maximal bicep curl. Submaximal performance was affected on all four four lifts. The greatest impairments were found later in the protocol, suggesting a cumulative effect of fatigue from sleep loss (Halson 2014).

In a recent study on sleep restriction, they looked at how people were affected by 8 hours, 6 hours and 3 10 hour sleep sessions in 13 nights. This study showed that the level of sleepiness increased when sleeping was restricted.  If we do not stick to a routine, our performance in athletics and life could be affected.  Keeping a sleep schedule is advised so these ups and downs don’t happen all the time.

Effects of Sleep Extension

The effects of sleep on performance are to extend the amount of sleep an athlete receives and how this affects performance. In a study using six basketball players, they slept more than 8 hours a day following 2 weeks of normal sleep habits. Faster sprint times and increased free-throw accuracy was noticed at the end of the sleep extension period. Their moods increased, with increased motivation and decreased fatigue. It was also noticed that increased the sleep time of swimmers from their usual sleep amount to 10 h per night for 6–7 weeks. Following this period, 15 m sprint, reaction time, turn time, and mood all increased.

Effects of Napping

Athletes who suffer from some degree of sleep loss can benefit from a nap, when a training session is to be completed in the afternoon or evening. Studies have investigated the effects of a lunchtime nap on sprint performance following partial sleep deprivation (4 h of sleep). Following a 30-min nap, 20 m sprint performance was increased, attentiveness was increased, and fatigue was decreased when compared with the no-nap trial. In terms of cognitive performance, sleep supplementation in the form of napping has been shown to have a positive influence on cognitive tasks following a night of sleep deprivation (2 h) (Halson 2014). Naps can reduce sleepiness and help with learning skills, strategy and form.

What to do!

There are major problems with sleep deprivation, in addition to reduced exercise performance. While those studies have not focused on athletes, some of the changes that occur in cognition, pain perception, immunity and inflammation, and metabolism and endocrine function may be relevant to the elite athlete (Halson 2014). It is important to get the recommended amount of sleep per day.  Some people can survive with little sleep but this can be a problem down the road.

Recommended Sleep Length by Age

1. Age 1 to 3 years old: 12 to 14 hours per night
2. Age 3 to 5 years old: 11 to 13 hours per night
3. Age 5 to 10 years old: 10 to 11 hours per night
4. Ages 10-19 years old: 8.5 to 9.25 hours of sleep per night
5. Adults: 7-9 hours of sleep per night

5 Tips for Getting more Sleep!

1. Get to bed and wake up at the same time.
2. Try to keep the same sleep schedule 7 days a week, if you’re partying on the weekend and you stay up late and wake up late, this can throw you off for the next week.
3. Avoid caffeine late in the day,caffeine can interfere with sleep. The effects of caffeine can last as long as 8 hours.
4. Take a warm shower or bath before bed, try to relax in the shower, clear all thoughts before bed
5. Try to relax your mind before bed, try not to watch tv and keep the room quiet. Whatever is going on in your life, try to forget in.

Reference:

1. Halson SL. Sleep in elite athletes and nutritional interventions to enhance sleep. Sports Med. 2014 May;44 Suppl 1:S13-23.

Written by Chris Barber, CPT