High-performance sleep. Are you getting enough?

Sometimes if you really want to step up your game and take performance to the next level, you really need to commit – to sleeping in occasionally. Or at the very least sleeping both more, and more effectively. Because sleep truly is the ultimate performance enhancer – boosting endurance performance, reducing likelihood of injury and illness, and is essential for strength gains and lean muscle mass, as well as cognitive function for skill acquisition, reaction times and strategy.

Studies show adequate sleep can reduce risk of injury by as much as 65% among adolescent athletes[i]. But the injury risk associated with poor sleep persists throughout our lifetime, while other research identifies poor sleep effects as having significant detrimental effects on peak muscular strength, vertical jump height and peak running speed, plus decreased respiratory efficiency and faster onset of fatigue[ii].

In other words, no training session will improve performance as much as some quality sleep – and if your training plan doesn’t prioritise quality sleep – then it’s time to reassess.

And for those who think that skipping another session for some extra sleep will hamper efforts at weight loss or fat loss – then reconsider. Weight loss, or body composition changes are more than just train/eat and an increasing number of studies show that sleep deprivation leads to weight gain and loss of lean body mass – both negative outcomes for athletes.

Grehlin is known as the hormone that stimulates appetite, while leptin is the ‘step-away-from-the-plate’ hormone that increases as we start to get full. Inadequate amounts of sleep (even in the short term), as well as stress and overtraining, can lower levels of leptin whilst increasing grehlin and cortisol (another hormone that correlates strongly with stress). Higher levels of cortisol are known to increase appetite but also the drive to consume high impact/energy foods – high sugar and high fat. This hormonal cascade promotes development of insulin resistance and inflammation – both of which can increase risk of being overweight (or make weight loss efforts very difficult), and also hamper training recovery and performance gains.

How much?
Experts recommend adults should be getting 7-9 hours sleep per night. However, just as important as the number of hours, is the quality of that sleep. During sleep, our brain and body move through three phases: light sleep, deep sleep, and REM sleep. Light sleep is when our parasympathetic nervous system kicks in. Our breathing slows, muscles relax, and heart rate slows down. As we move into deep sleep, our brain activity becomes long, slow delta waves. Finally in REM (Rapid Eye Movement) sleep – which is also when we dream – our muscles are completely relaxed and our brainwaves become rapid again.

Quality, restorative sleep: where all the magic happens for cognitive processing and muscle repairs – happens during deep sleep and REM sleep. These stages can make up 30-40% of our total sleep time, but are also the stages that are most severely affected by disturbances, temperature changes, and substance use.
Want to improve sleep quality?

Stick to a schedule: You have a body clock – sticking to waking and falling asleep within the same window helps promote good sleep.

Wind down: Take a warm shower or bath 1-2 hours before bed. Research shows this can help reduce time taken to fall asleep and increase sleep quality. A warm shower helps facilitate heat loss from the body, dropping core body temperature which regulates circadian rhythm. Even in hot weather a warm shower followed by AC or fans will aid in sleep, plus help relax muscles before bed.

Watch your (sleep) hygiene:

• Minimise disturbances by switching off lights, using block-out blinds, avoiding screens and your phone in the hour before bed.
• Make your bedroom a nice place to sleep – is your bed comfortable? Are your sheets clean? Is your room temp optimal for sleeping? (between 17-20 degrees)

Eat to sleep: There are foods and habits/timings that either promote sleep or hinder sleep.

Foods that promote sleep:

• Tryptophan rich foods (chicken, turkey, dairy) boost serotonin levels, while complex carbs (eg brown rice, sweet potatoes) stimulate insulin response and prompt sleep onset.
• Vitamin D (sunlight plus fatty fish, eggs, dairy) helps regulate circadian rhythm, assists with sleep quality and reduces risk of sleep issues such as insomnia.
• Magnesium can help muscles relax and calm the nervous system. Include foods such as nuts and seeds, dark leafy greens and fish.
• A nutrient rich diet reduces inflammation, improving sleep quality and lowers risk of anxiety and restlessness
• Tart cherry juice and kiwifruit also have research backing them as aiding in sleep quality.

Foods that hinder sleep:

• High sugar diets which disrupt insulin response and circadian rhythm.
• Alcohol – may give the illusion of helping you fall asleep, but increases sleep disturbance and lowers sleep quality.
• Caffeine – avoid caffeine in the afternoon.
• Large meals right before bed, very fatty or spicy meals can also reduce ability to fall asleep as well as sleep quality.

1. “Chronic lack of sleep is associated with increased sports injuries in adolescent athletes.” Milewski MD, et al. (2014) https://pubmed.ncbi.nlm.nih.gov/25028798/
2. “Ongoing study continues to show that extra sleep improves athletic performance.” Mah C, et al. (2008) https://pubmed.ncbi.nlm.nih.gov/25028798/