We all know that getting at least 8 hours of sleep a night is important for being healthy, but why? And how does it affect our training?

How important is sleep to building muscle?

Not only does your body go through different stages of recovery as you sleep, how your body rested affects how you perform and eat the next day.

Research by the Annals of Internal Medicine discovered that having less than seven hours of sleep per night can reduce and undo the benefits of dieting in order to lose weight in combination with an exercise regime. In the study, participants were put on different sleep schedules. When their sleep was cut back the amount of fat lost was cut in half, they felt significantly hungrier, were less satisfied after meals and lacked the energy to complete their exercise regime. Overall, their fat loss was reduced by 55% after inadequate rest.

Another study on sleep monitored Stanford University players for the varsity basketball team. Researchers asked the players to increase their sleep time to roughly 10 hours per night, whereas they were used to sleeping for 6-9 hours. After they had slept more, the players had faster sprint times, their shooting accuracy improved, their free-throw percentage increased by 9% and three-point-field-goal percentage by 9.2%.

The American Journal of Clinical Nutrition found that poor sleep can increase the levels of our stress hormone cortisol. This increase in cortisol will impact the body's ability to repair damaged muscle tissue, increase weight gain and elevate blood pressure.

Sleep deprivation has also been seen to decrease production of glycogen and carbohydrates that are stored for energy use during physical activity. In short, less sleep increases the possibility of fatigue, low energy, and poor focus at game time. It may also slow recovery post-game.

A recent study found that going for 18–20 hours without sleep had the same negative impact on performance as a blood alcohol level of 0.1 (0.08 is considered legally drunk in the US).

What is recovery in training?

Whilst we are sleeping our bodies release hormones which are essential for fitness recovery. The series of events that occurs once we shut our eyes is divided into 4 distinct categories.

Sleep Stage 1:

The first stage of sleep is characterised by drowsiness, slowing brain activity and shutting your eyes. This stage of sleep is the most easily disrupted. When it comes to muscles, at this stage they are still quite active and the eyes will roll around, often opening and closing. At this stage breathing becomes more regular and heart rate begins to slow, sudden jerks are common in this phase as sleeping takes over waking.

Sleep Stage 2:

Stage two typically constitutes 45-50% of sleep for adults. During this stage muscle activity decreases along with the consciousness of the outside world.

Sleep Stage 3:

Stage 3 sleep is the deepest stage of sleep your body enters. Your brain is resting with very little activity, so the blood supply available to your muscles increases, delivering extra amounts of oxygen and nutrients which facilitate their healing and growth. Your pituitary gland also releases a shot of growth hormone which stimulates tissue growth and muscle repair. Muscles and tissues are rejuvenated and new cells are regenerated during this phase of sleep.

REM Sleep:

REM sleep is the phase of sleep which is characterised by rapid eye movements. This phase of sleep is where the brain is most awake, but the rest of the body becomes almost paralysed. This is thought to be a built in measure to protect us from hurting ourselves during vivid dreams, as this is the phase of sleep where most dreams and or nightmares take place.

Our sleeping pattern isn’t chronological and we may go through these cycles multiple times, however when it comes to recovery, we can see that stage 3 is our most valuable sleep stage.

How many hours of sleep does an athlete need?

Most people need about 6-8 hours of sleep per night, but when you’re training this can be significantly more. Just as athletes in training typically need to consume more calories, athletes in training typically need an extra hour of sleep, if not more.

What happens to recovery if we don't get enough sleep:

• Chronic sleep loss can result in a 30 - 40% reduction in metabolism.
• Sleep loss causes an 11% reduction in time to exhaustion.
• 2 days of sleep restriction can lead to 3 times the increases in lapses of attention and slowed reactions.
• 1 rep max bench press is reduced by 20 lbs after 4 days of disturbed sleep.

* According to research conducted by Zeo sleep manager.

These athletes clearly recognise the benefits of a good night's sleep on their performance, with Tiger Woods being our very own anomaly.

What are the effects of lack of sleep?

Not only will lack of sleep put your recovery under threat, it can have considerable effects on your health. Research has found:

• Going to bed too late doubles the risk of breast cancer.
• The risk of heart disease is increased by 100% if you get less than 7 hours sleep per night.
• If you are sleep deprived you are 20% more likely to die in the next 20 years.

How can I improve my recovery with sleep?

1. Increase your magnesium intake. Magnesium, found in foods such as halibut, cereal, mixed nuts, soybeans and spinach will help to improve poor sleep.
2. Eat a diet which combats inflammation. Eating a diet rich in colours will help to combat inflammation, which can lead to a restless night's sleep. Turmeric spice is a great aid for this.
3. Take naps. If you struggle to sleep at night, napping throughout the day could be the answer to aid your recovery.
4. Cut out stimulants at least 5 hours before you try to sleep. Caffeine can keep you awake at night or give you a restless night's sleep. Caffeine is a known central nervous system stimulant that takes 45 minutes to be completely absorbed by the body, and it takes approximately three to four hours to be completely eliminated and in some people, this could be even longer. Even if you're one of those types of people who can drink coffee and go right to sleep, it may still interfere with the quality of your sleep.
5. If you still struggle to sleep after a tough training session, get checked with your GP for sleep apnea.