Sleep more, exercise better

Eating well is recognised as a key part in maximising athletic performance. Adequate sleep is also a vital, but often neglected, source of energy for exercise. Harnessing both nutrition and sleep can help enhance your athletic ability or at least give you the boost you need to start exercising regularly.

Why exercise needs sleep

When we sleep, our body produces the human growth hormone [HGH], which allows for muscle growth and repair. Sleep improves reaction time, muscle memory, motivation and energy. Researcher Cheri Mah of the Stanford University found that varsity female tennis players were able to run sprints significantly faster and hit better shots with extended sleep.

The different stages of sleep strengthen our brain connections that control muscle memory. Rapid eye movement [or REM] sleep is the stage of sleep responsible for dreaming and promoting learning. This stage helps lay down in long-term “muscle memory”, the skills we practise in a day.

Another important component of sleep, the “sleep spindles”, occurs only between the sixth and eight hour of sleep. These spindles represent cascades of calcium in our brain. The calcium [which cannot be taken from pills] causes the melding of a step-by-step athletic motor sequence into an automatic, fluid and fast movement.

Consider a golf swing; you can never hit the ball perfectly if you focus on each step in the process—the swing needs to be rapid and automatic. If you truncate your sleep, you will miss those last important two hours of sleep in the eight hour sleep-cycle. You will therefore miss the opportunity to be a better athlete. So, many sports heroes, like cyclist Lance Armstrong and Olympic gold medallist Sarah Hughes, have found that extended sleep contributes greatly to their performance. It is often the key to obtaining that “extra edge” that significantly improves what your body can achieve.

How much should I sleep?

The average adult needs about eight hours of sleep each night, yet the vast majority of us get less than six. Those who exercise need even more sleep because of the physical strain they undergo. To boost our exercise performance, most of us need to add an extra hour to what we usually get each night.

How do I eat for optimal sleep?

Several dietary precautions can be taken to allow maximum sleep and fuel your body for peak performance.

• Avoiding a late dinner can improve quality of sleep because it will catalyse a dip in body temperature and promote sleepiness.
• Alcohol and hard-to-digest foods disrupt sleep when consumed too close to bedtime. While alcohol destroys sleep periods that permit body restoration and muscle memory development, hard-to-digest foods interfere with sleep quality. Examples of foods to avoid include spicy foods, dairy, garlic and meats.
• Some foods actually help us sleep. Carbohydrates cause the release of tryptophan, a chemical that is converted into serotonin in the brain, which makes us sleepy. Proteins have the opposite effect.

They reduce the amount of tryptophan entering the brain, making us more alert. Avoid consuming protein within four hours of bedtime. A night-time snack of carbohydrates can be satisfying following an early high-protein dinner.

The benefits of sleep and nutrition are bidirectional; not only does good nutrition aid sleep, but adequate sleep also helps you make healthier food choices. This maximises athletic performance by providing the fuel you need, when you need it.

Is time of exercise related to sleep?

Yes. Our bodies are designed to perform certain functions at certain times of the day. We have internal clocks that operate on circadian rhythm. Temperature is one indicator as well as a control of circadian rhythm. During sleep, our body temperature drops and slowly increases after we wake up. Jump-starting this warming process with early morning exercise can cause overheating and exhaustion. Hence, it’s best to avoid the early morning exercise routine.

Also, by getting up early, we miss necessary sleep. In addition, a fluid has been building between our spinal discs throughout the night. If we fail to adequately stretch before morning exercise, it is likely that we might cause lower back pain and increase the risk of serious injury such as a herniated disk. However, many of us insist that our only free time is early morning. If you must exercise early in the day, take all the necessary precautions to protect your body.

Exercising from 5pm–7 pm is the best as it does not interfere with our circadian rhythm. Our bodies cool off from 2pm–4pm, resulting in an afternoon dip in alertness. At this time, our internal clocks are not in the process of heating or cooling, allowing for alertness and optimal exercise. If we exercise at night, when our bodies are attempting to cool down, we wake up and don’t get restful sleep after that.

If you want your body to get up and go, fuel it with the food and sleep it needs to get the most out of exercise.

This was first published in the August 2011 issue of Complete Wellbeing.