An article explaining the body clock, its importance in exercise, and suggesting the best times to work-out according to your body’s internal environment.
A lot of people want to start an exercise habit, but few are aware of the best time to do it. Should it be done in the morning, to start the day off right? Lunch, when the office gym is empty? Or after coming home from work, when you don’t have to worry about anything else?
Because exercise is a physical activity, it gets affected by our physiological profiles throughout the day. And these physiological states are determined, in part, by melatonin. What exactly is melatonin? It is a chemical message – a hormone – that governs our circadian rhythm. The circadian rhythm is your basic 24-hour body clock. Melatonin has a lot of responsibilities, and it tells your body when nighttime has come, thus inducing sleep; it also detects when light has hit your eyes, signaling daytime. When daylight is detected, melatonin stimulates the release of other hormones so you increase alertness, until finally, you wake up. Ever notice how it gets harder to fall back to sleep once the sunlight hits your face? Similarly, you tend to sleep with the lights off. That’s the work of melatonin.
Since melatonin levels vary throughout the day, your circadian rhythm functions like a cycle. At certain times of the day, you’re more alert. Sometimes you’re better at coordination. And there’s a certain time of the day when you’re psychologically fired-up to do something challenging, like going for a five-mile run. For example, at around 4:30 am, your body is at its lowest temperature – so it might be hard to warm up your muscles in preparation for physical activity. At 10:00 am, however, you have very high alertness. At 2:30 pm, you have the best coordination – but reaction time peaks at around 3:30 pm. However, at 5:00 pm, you will have the best cardiovascular performance and muscular strength you can expect from your body.
But what does this mean for your work-out? It just means that different kinds of physical activity are best suited to different times of the day. In the morning, running would make sense because you ease into raising your body temperature, as opposed to suddenly engaging in some high impact boxing session. Early afternoon can be the best time to engage in some competitive sport like tennis, to take advantage of fast reaction times; there’s also dancing, to maximize your body’s increased levels of coordination. And of course, there’s always high-intensity interval training, drills, sprints or some football best suited to peak body temperature, cardiovascular efficiency and muscle strength that’s expected from the late afternoon to early evening.
It’s certainly a good idea to plan your work-out, because it makes you more likely to make a habit of it. But some things are easier said than done. So we learn how to take any help we can, especially one that our bodies provide naturally. The key is to optimize your basic physiological processes. Make sure you’re that when you’re exercising, you’re working with your body, and not against it.
But remember that in the end, the first and foremost requirement of exercise is that you do it. This is a fact that doesn’t vary throughout the day. Now is the best time to start.
Source: Koeppen, B. M. & Stanton, B.A. (Eds.). (2010). Berne and Levy: Physiology (6th ed). Philadelphia, PA: Mosby Elsevier.