The relationship between exercise and body weight is often complicated. Some people lose a lot of weight while playing sports, while others lose few pounds, and sometimes go so far as to gain some. This variability interested the team of scientist Erik Willis, from the University of North Carolina, in the United States.
For about a decade, researchers have overseen a comprehensive review of how regular exercise influences body weight. Their latest findings were published by the journal The International Journal of Obesity. During this study, about 100 overweight, previously inactive young men and women trained five times a week in a lab. They jogged or sweated up to burning 600 calories per session.
Move before noon
After ten months, they had all lost weight. But the magnitude of the losses fluctuated a lot from person to person, while the amount of exercise was the same. When the researchers tried to identify what distinguished the two groups, they found very little difference. They then began to think about other possibilities, perhaps unexpected, factors that may contribute to the variability in weight loss. However, science is increasingly interested in the circadian rhythm which, for example, affects weight control depending on the timing of meals.
The researchers, therefore, reviewed their data, focusing on the training schedule of the study participants. Surprise: people who used to train before noon had lost more weight, on average, than those favoring exercise after 3 p.m. The morning exercise group also tended to be slightly more active throughout the day, and at eat a little less. These differences were barely noticeable, but they may have cumulatively contributed to variations striking in the number of pounds lost.
The lead author of the study, Erik Willis, is keen to clarify: “I wouldn’t want people to think it’s not worth exercising if you can’t do it first thing in the morning. Any exercise, at any time of the day, will always be better than nothing. “