Is there a correct time to exercise? It’s a good question and the answer – as with so many of life’s big questions – is ‘yes, but...’

It’s highly likely that, for a range of reasons, there’s an optimum time to exercise for each person. What time of day that is, however, will depend on such a large number of factors that it’s likely that – for anyone but the elite athlete, competitive bodybuilder or exercise obsessive – identification of the time in question is more trouble than it’s worth.

For example, while research suggests that the lungs function best late in the day, certain hormones that regulate response and adaptation to exercise peak in the morning. Likewise, while muscle force might peak in the evening, motor co-ordination and concentration are way past their best by this time, as is pain tolerance.

If you know the exact balance of physiological, cognitive, emotional and performance variables required to perform at your best and to recover optimally, you might be able to identify the optimal time for specific goals. But you probably can’t rely on the published research to do so. Research conducted on large populations rarely generalises to individuals, meaning that you will have to use a lot of trial and error to identify the optimal times for each variable for yourself. To make things even worse, there’s a strong chance that relationships between time of day and performance variables might change with the season, temperature, stress and a number of other factors.

Train when you can as best you can. If you feel better training in the morning, if you see results and if it works for your lifestyle, that’s the time to train, irrespective of what the research says. If you want to be a champion, you may need to look deeper into your internal rhythms, but be prepared for a complex journey!

The ideal training time is different for each muscle group. According to the Chinese Organ Clock philosophy, each muscle is associated with an internal organ in the body, and each organ has a circadian rhythm that includes daily phases of elevated activity (ideal training time) and recuperation (unfavourable training time). While muscles are improved by physical activity and sports, the state of organ function is therefore co-responsible for muscle health.

This is valuable information for drawing up personalised training schedules, as it means there are ideal times to train each muscle group. For example, avoid isolated training of hamstrings and biceps femoris between 5pm-7pm (recovery phase of connected large intestines) and train abdominal and quadriceps muscles between 1pm-3pm (optimal time for small intestine).

If a person has muscular problems, this may be due to injury, but it might also be related to hidden problems with the organ associated with that muscle. Problematic muscle regions should be trained gently and at the right times: if function-impaired muscles are stressed by inappropriate training, then (besides poor results) negative repercussions in the associated organ system cannot be ruled out.

Of course, it isn’t always possible to train at the ideal time for each individual muscle. In this case, when working out at less favourable training times, the training should support the muscle’s recuperation through stretching and light, steady work designed primarily to stimulate metabolic exchange.

The best answer is: ‘it depends.’ Humans are both complex and adaptive. We have diverse patterns and personalities and we’re constantly adjusting to shifting life conditions. Time is only one factor to consider in relation to exercising. I dislike evening exercise, yet that’s when my aikido classes are. Will I give up my beloved aikido because of its timing? Never. For people who have a particular practice or sport, time is not the pivotal factor.

Let’s consider personality. My research shows that we gravitate toward activities that mirror our psychology. If you’re extroverted and a thrill-seeker, you want to be social and stimulated. Your biological clock may urge you to exercise at 2pm, but friends you ‘play’ with aren’t around then, and the exercise world at that time looks like a treadmill. So you’ll need to apologise to your internal clock and exercise when the racquet court – and your preferred partner – are available.

Here’s another thought: exercise has many faces. No matter what, I cannot get myself to reliably tie on my running shoes at 6am, but I do exercise in the morning. I do yoga and, in the summer, I eagerly leap into the lake for a half-hour swim. However, I don’t think I’ve ever pumped iron before breakfast. Some movement forms feel better to us at different times of day, and these can slide in seamlessly at appropriate moments.

Final comment: is your life schedule predictable and totally under your control? If so, you’re in a distinct minority. It’s increasingly a 24/7 world that we have to navigate as best we can. Embrace diversity and broaden your definition of exercise.