The most effective way to optimise our sleep quality is to improve our sleep hygiene. As you may have already assumed, sleep hygiene refers to the way we choose to practice our sleep habits. All humans have a biological circadian rhythm that controls changes in our body temperature, the release of circadian hormones and even our immune responses. We can help optimise our sleep quality by falling asleep when our body temperature peaks, which is usually in the evening. However, we can also re-train our circadian rhythm by having consistently late nights, which result in later peak temperatures. Inconsistent bed times and poor sleep routine may leave you unaware of your optimal sleep time.

So…how do we know when our optimal sleep time occurs?

Since it is not practical routinely monitor our body temperature, the best approach is to maintain consistent bed times and sleep duration.

There is little doubt surrounding the claims that moderate exercise and fitness training improve sleep, especially in people who suffer from sleep disorders that are caused from being overweight. The most obvious sleep stage affected by exercise is the deep sleep stage. In fact…training can initiate a 3-fold increase in deep sleep. Because deep sleep facilitates the release of growth hormone we may even go as far to say that deep sleep is age preserving. It is also undoubted that people who exercise feel younger. Deep sleep occurs during the first third of the nights sleep and is compromised by delayed bed times. To improve sleep quality in terms of deep sleep it is important to avoid late nights or disturbing sleep environments.

Now we have mentioned growth hormone you begin to appreciate the value of deep sleep and are probably left asking…"Is there anything else I can do to enhance deep sleep?"……your answer is "yes", so keep reading….

Deep sleep should also occur during naps between high intensity sessions.

There are certain hypnogenics (sleep medication) on the market. Zolpiden, otherwise known as by its trade name has been found by researchers in 1995, to act on the glutamate pathways in the brain to induce and enhance deep sleep. Hypnogenics are banned in some sports such as fencing, archery and shooting but are not banned out of competition in any sport. However, sleep medication is only available by doctor's prescription and becomes ineffective with long-term use.

A less controversial way to enhance deep sleep is to vary your temperature within a few hours of going to bed. This can be achieved by hot and cold showering before bed.

The second important sleep stage to discuss is rapid eye movement sleep (REM). This sleep stage is often reduced, possibly to the prolonged time spent in deep sleep. However, in a normal sleep pattern, REM dominates the last two thirds of our nights sleep. Unless morning physical exertion raises the demand for deep sleep our afternoon sleep is also likely to be dominated by REM. We can describe REM as the 'default' stage of sleep but we need to consider that too much REM has adverse side effects. For example, excessive amounts of REM sleep have been associated with depression and de-motivation. A common mistake to make is the long 'recovery' sleep-in or long afternoon nap. They can leave us waking de motivated and depressed, making it easier to postpone our planned training session.

Although we strongly discourage excessive REM sleep, waking from the REM stage is the natural process of terminating the sleep cycle and results in a greater feeling of re-freshness.

REM sleep is the stage of sleep in which we dream, so we can tell when we wake from REM because we usually remember our dream. After spending a lot of time in REM our dreams become more intense. Dream intensity could be a guide that we have overslept. However, dream intensity is also heightened when we finally enter REM sleep after being REM deprived.

In summary, to exploit the benefits of sleep on sport, and also on health and fitness, we must first assess what aspect of performance needs improving. When your levels of motivation and mood are impaired, you can decrease your amount of REM by limiting the duration of sleep (for example avoiding sleeping-in). However, prior to maximal physical performance it is important to not be REM deprived, otherwise, the required effort for the performance is likely to be greater. It would also be beneficial to wake from the REM cycle, for both cognitive and physical morning performances.

Tahnee Kinsman.
Sleep Research Physiologist
Australian Institute of Sport.