The research from the Karolinska Institutet in Sweden and the University of Copenhagen in Denmark, and published in the journal PNASshows that the mice that did exercise in an early active phasewhich corresponds to morning exercise in humans, increased their metabolism more than mice that exercised at a time when they normally rest.
Physical activity at different times of the day can affect the body in different ways, since biological processes depend on the circadian rhythms of cells.
To determine how the time of day you exercise affects fat burning, researchers from the Karolinska Institutet and the University of Copenhagen studied the adipose tissue of mice following a high-intensity exercise session performed in two points of the daily cycle: an early active phase and an early rest phase that corresponds to a late morning session and at the end of the followingnoon, in humans.
The researchers studied various markers of fat metabolism and analyzed which genes were active in fat tissue following exercise.
Better at the end of the morning
The researchers found that physical activity in an early active phase increased the expression of genes involved in the breakdown of adipose tissue, thermogenesis (heat production), and mitochondria in adipose tissue, indicating a higher metabolic rate. These effects were seen only in mice that exercised in the early active phase and were independent of food intake.
Mice are a well-established model for human physiology and metabolism.
“Our results suggest that late-morning exercise might be more effective than late-night exercise in terms of boosting metabolism and fat burning, and if this is the case, it might prove valuable for people with overweight,” says the teacher Juleen. R. Zierath from the Department of Molecular Medicine and Surgery and from the Department of Physiology and Pharmacology of the Karolinska Institutet.
Mice and humans share many basic physiological functions, and mice are a well-established model for human physiology and metabolism. However, there are also important differences, such as the fact that mice are nocturnal.
“He right timing seems to be important for the body’s energy balance and to enhance the health benefits of exercise, but further studies are needed to draw reliable conclusions regarding the relevance of our findings to humans,” says Professor Zierath.
