How Much Sleep is Enough?
Research has shown that getting a minimum of 10 hours sleep per night during the training week can positively impact athletic performance. Reaction times are sharpened, sleepiness during the day is reduced, and overall mood is elevated, but how many hours of sleep do footballers get on average?
In a separate study centred on assessing the impact of night matches on elite players, the average amount of sleep achieved during a typical training week was recorded as between 6 and 7 hours. After playing a night match with a kick-off time of 6pm or later, the average amount of sleep achieved dropped to around 5 hours.
Further studies have concluded that less than 7 hours of sleep per night negatively impacts performance, with the most significant effects being a drop in cognitive abilities (your ability to think, learn, remember, and process information) and a rise in pro-inflammatory cytokines circulating in your body.
These are molecules secreted by the immune cells and their purpose is to upregulate, or make worse, the body’s inflammatory reactions, including fever, inflammation, and tissue breakdown.
Sleep Study Statistics
In the above study centred on the effects of night matches on sleep, several changes in normal sleep patterns led to getting less overall sleep after a night match.
Getting to bed later: On average, players got to bed 2 hours later on night match days compared to normal training days.
Getting up at the same time: Getting up times remained the same despite getting to bed later, and this was due to scheduled recovery sessions.
Taking longer to get to sleep: After a night match, players reported taking longer to get to sleep compared to normal training days.
And getting poorer quality sleep: The quality of sleep achieved after a night match was rated poorer by the players compared to normal training days.
The study tracked the sleep habits of 20 elite football players over a 3-week period which included 5 competitive night matches.
Wrist monitors were worn in bed to provide objective measures of sleep duration, and sleep diaries were kept by the players to record subjective measures of changes in sleep patterns, including the quality of each night’s sleep.
The Ramifications of Less Sleep
Everyone experiences a night of poor sleep from time to time, but getting to bed early the following day is usually all it takes to catch up and shake off the general grogginess a lack of sleep creates.
The difficulty for players taking part in regular night matches is that the lack of sleep also becomes a regular happening, and repeated nights of poor sleep can lead to chronic sleep debt.
The implications of this in terms of football performance are significant.
Getting 10 hours of sleep will optimise your reaction times, so sleep debt will do more than make you moody and irritable with your teammates, it will slow your reactions, impact your sprinting ability and increase your potential to pick up injuries.
The increase in pro-inflammatory activity could also lead to chronic inflammation which brings with it potential long-term health concerns.
Inflammation is your body’s response to the type of muscle damage that could occur in training or a hard match and it’s part of the natural repair system. However, chronic inflammation elevates the responses to a level that makes them harmful rather than helpful, creating on-going symptoms such as joint pain and fatigue.
Good Sleep Habits
The reported difficulty in getting to sleep after a night match compared to a normal training day could, in part, be connected to playing under floodlights and the potential for this to interfere with the body’s internal clock.
It’s also known that the blue light emitted from computers, smart phones, tablets, and TV screens can interfere with sleep.
Studies have shown that using electronic devices immediately before going to bed causes a state of alertness that makes it more difficult to get to sleep.
In the sleep study centred on night matches, most of the players reported watching TV or using devices in the two hours before going to bed, so blue light may also have interfered with the body’s internal clock.
Other factors that may have contributed to getting less overall sleep include:
Caffeine consumption prior to the match: Caffeine is a known stimulant that can increase alertness, and some studies suggest that just one cup of coffee taken 6 hours before bedtime can shorten your overall sleep by as much as an hour.
Alcohol consumption after the match: Several studies have concluded that alcohol can help you to get to sleep quicker, but the quality of your sleep is much poorer. Alcohol increases the production of adenosine, a sleep-inducing chemical produced in the brain, making it easier to get to sleep, but it also blocks REM sleep, considered the stage of sleep that’s most restorative, leading to waking up feeling groggy and tired.
And napping during the day: Studies on the effects of daytime naps on night-time sleeping have shown optimal nap lengths to be between 10 and 20 minutes. In the afternoon prior to night matches, players took naps ranging from 30 minutes to 90 minutes which may then have interfered with the ability to get to sleep at night. Naps lower adenosine levels in the body, so the longer the nap, the longer the gap before feeling sleepy again.
Conclusion and wider impact
The findings of the study on the impact of night matches on sleep in elite footballers suggest that the quality of sleep achieved by players at this level is sub-optimal and lower than expected.
For this reason, further studies are needed to gather information on the normal sleep habits and patterns of competitive athletes at different levels across a wider range of sports.
The statistics gathered indicate that playing night matches with kick-off times of 6pm and later does have a significant impact on sleep compared to normal training days, and therefore playing regular night matches could lead to on-going sleep disturbances and a cycle of poor sleep that would negatively impact performance.
The lack of quality sleep after a night match could lead to daytime naps the following day which could then interfere with getting to sleep the following night… and so the cycle continues, but the findings of the study also suggest that players need clearer guidance on better methods of promoting sleep.
Out of the 20 elite players in the study:
- 75 per cent reported using technology such as phones, computers, and TV viewing to promote sleep
- 15 per cent used prescribed sleep medication
- 15 per cent used a muscle-relaxant medication
- 10 per cent used other methods of relaxation such as reading a book
These statistics indicate that poor sleep hygiene may be influencing the poor sleep cycle and players need to work on finding better ways to unwind after a night match.
The best ways to promote restful sleep are always going to be highly individualised, but good sleep hygiene recommendations include:
- Avoid caffeine, including painkillers containing caffeine, for at least 4 hours before going to bed
- Avoid alcohol for at least 3 hours before going to bed
- Avoid using electronic devices that emit blue light for at least 2 hours before going to bed
- Avoid spicy foods or high fat foods that may cause indigestion
- And establish a relaxing bedtime routine that promotes drowsiness, such as taking a bath or reading a book.
The elite players in the study (playing an average of 2 night matches per week) ate a carbohydrate-based (low-glycaemic-index) pre-match meal 3 hours before kick-off.
The after-match routine then involved immersion in a cold bath followed by eating high-glycaemic-index carbohydrates and protein foods such as milkshakes, sports drinks, soup, sandwiches, and yoghurt.
Pre and post-match routines such as these are based on the findings of research centred on maximising performance and recovery, and they are well-established in football.
The findings of the study on the detrimental effects of night matches on sleep among players indicate that issues impacting sleep need to be factored into training schedules by coaches (the timing of recovery sessions, for example) and players need better education in terms of following the good sleep hygiene guidelines to help establish routines that will promote restful sleep when normal routines are disturbed.
The study found that elite players achieved less sleep after night matches compared to normal training days and the knock-on effect of this is the potential to enter a cycle of poor sleep and eventual sleep debt.
The implications of chronic sleep debt in footballers is a drop in reaction times and overall performance and an increase in the potential to pick up injuries, leading to the conclusion that more emphasis must be placed on establishing good sleep hygiene practises to promote optimal sleep in players when match times may disrupt normal sleep patterns.