Men and women who work out will get different results depending on the time of day they do their physical activity, according to a new US study published by Frontiers in Physiology.
Posted at 12:52 p.m.
By comparing men and women who trained either in the morning or in the evening, researchers at New York’s Skidmore College found, at the end of a 12-week program, that women who trained in the morning lost more weight, while those who trained at night added more upper body strength and power.
No such difference was found in men. However, men who exercised later in the day significantly lowered their blood pressure. They also lost more fat than women, even though they performed the same exercises.
“Many people who train will be disappointed because the results will be less than those desired,” reacted Professor Pascal Imbeault, from the School of Physical Activity Sciences at the University of ‘Ottawa.
“There are many factors that influence this lack of response or reduced training response. So there is perhaps precisely the aspect of chronobiology that comes into play, and that is a factor that we were unaware of several years ago. »
The conclusions of the New York study are in line with those of previous studies.
For example, a study published in 2021 indicated that the best time to practice strength and power exercises is in the late afternoon, when our body temperature is at its highest.
A year earlier, a study found that men who exercised between 3 p.m. and 6 p.m. significantly improved their blood sugar control and insulin sensitivity, compared to those who exercised between 8 a.m. and 10 a.m. This is particularly relevant for men who have, or are at risk of having, type 2 diabetes.
That being said, Professor Imbeault continues, science already knows that women tend to be more “morning type” and men more “evening type” (what is called their “chronotype”), which could explain the results obtained by the New York researchers.
“So I would expect that the women who were training in the morning would probably have a better response to their training than those who were in the evening group,” he said.
The first lesson to be learned from this study, he continues, is therefore to ask yourself, before embarking on a training program, at what time of the day you feel the most “awakened” or the most “vigorous”. , since that’s when you’re likely to get the best answers.
“The ideal time to train is when our body temperature is at its highest, because that’s when our body is in action, when it is activated,” explained Professor Imbeault. This is when we are in an optimal zone and it is most natural to push hard. »
Some smart watches now allow us to measure our body temperature in real time, and therefore to identify our chronotype, he adds.
He cites the example of the runner who goes out alone every morning at 6 a.m. and the woman who trains in the gym at the start of the evening, according to their respective chronotypes, but also because the first works very well alone and the second needs the presence of others to be motivated.
This could explain why, in the New York study, participants who trained in the morning lost weight, while those who trained in the evening gained muscle.
“But I would be careful before concluding that to lose weight, you absolutely have to train in the morning, concluded Professor Imbeault. It’s normal for me to have had a better response in females because they are naturally more of a “morning type”. If someone is asked to get out of bed at 5:00 a.m. to work out when they’re more of a “party type,” it’s almost guaranteed failure. »