It is said that our bodies have clocks — body clocks. It might be truer to say our bodies are clocks. Recent advances in the understanding of the circadian rhythm, the 24-hour cycle of sleep and wakefulness and related processes, have revealed that the functioning of our bodies is affected far more extensively by circadian rhythm than was previously known. We now know that one out of every 10 genes in human DNA operates in 24-hour cycles.
In practical terms, what this new knowledge is telling us is that our bodies really want us to do certain things at certain times, namely sleep, wake, eat, be active and rest. When our behaviour defies the programmemed preferences of our body clocks, our bodies do not function as well as they should. If we sleep too little or too much, or if we eat when we shouldn’t or don’t eat when we should, our health is compromised. Our metabolic systems seem to be most affected when our lifestyle gets out of sync with our circadian rhythm. People who are chronically sleep deprived, for example, are more likely to become overweight or diabetic. And for athletes there are additional consequences.
“One of the problems that athletes have is that their lifestyle is fighting what their normal circadian rhythm is,” says Robert Portman, Ph.D., co- author of a new book, “Hardwired for Fitness,” which presents a diet and exercise programme based on aligning behaviour with circadian rhythm. “When that happens, you create metabolic inefficiencies.” For example, the athlete’s muscles might lose some of their ability to burn carbohydrates, which is critical to performance in workouts and races.
Circadian science suggests there is a right time for a triathlete to do everything. A triathlete who does everything at the right times over a 24- hour period has lived what we might call a perfect day. And a triathlete who lives a perfect day every day will realise his or her full potential in races. Of course, not enough is known to rigorously define a triathlete’s perfect day, and even if we knew everything, it would still be impossible for anyone to be perfect every day. Nevertheless, it’s a worthwhile exercise to define a perfect day in general terms.