Bodybuilders who train in the evening grow faster
The best time to do weight training is in the evening, say Australian sports scientists who measured hormone levels in young natural power athletes. Training in the evening probably results in more muscle bulk, according to the researchers.
The scientists did tests with thirteen bodybuilders who were studying at the university. They divided their subjects into two groups: bodybuilders who trained in the mornings and those who trained in the evenings.
So what is the best time of day to train, the Australians asked. Most sports writers say that training in the morning is good because the testosterone levels are higher at that time of the day. Dissidents, on the other hand, say that in the morning levels of the stress hormone cortisol are higher. Because of this, bodybuilders are better off training later in the day, say the dissidents. So who’s right?
The researchers first compared the two groups. The evening trainers looked better in the comparison, but the number of subjects was so small that the differences between the groups were not significant.
After that the researchers measured the cortisol and testosterone levels in their test subjects, at six o’clock in the morning and at six o’clock in the evening. This was done before the test subjects did their training. As you can see, in both groups the testosterone and cortisol levels were higher in the morning.
The Australians then measured the cortisol and testosterone production during and immediately after the training session. The graph below shows the testosterone curve for the morning group. The training session lasted an hour. Look at the curve with the solid black circles. As you can see, both testosterone and cortisol levels declined during and after the training. All test subjects did the same training programme, by the way.
Then the researchers combined the information into one graph, which shows the relationship between testosterone and cortisol. The smaller the ratio, the less catabolism going on in the body. In the figure below, the curve with the dark circles shows the ratio in the morning group. The curve with the white triangles shows the ratio in the evening group.
The conclusion that the Australians draw is not surprising. The best time to do weight training is late in the afternoon or early in the evening. At that time of the day the ratio between endogenous catabolic and anabolic hormones in the body is at its most favourable.
Influence of Circadian Time Structure on Acute Hormonal Responses to a Single Bout of Heavy-Resistance Exercise in Weight-Trained Men - Chronobiology International: The Journal of Biological and Medical Rhythm Research