The surprising benefit of exercising during this time of day

The more we learn about the intricate processes that govern metabolism and sleep cycles the better we’re able to optimize the value of healthy activities.

Just this week researchers from the University of Copenhagen and the University of California, Irvine released a new study delineating the time influenced ways our bodies respond to the physical exertion.

“While the timing of food intake is important, it is unclear whether the effects of exercise on energy metabolism are restricted to unique time windows. As circadian regulation is key to controlling metabolism, understanding the impact of exercise performed at different times of the day is relevant for physiology and homeostasis,” the authors wrote in the paper.

Because humans are diurnal animals, our cells are better equipped to metabolize sugar and fat sources during the day. In the evening, we lose this particular advantage but extend our body’s energy expenditure, which means we are able to burn a larger number of calories in a relatively short amount of time. 

The new study compellingly demonstrates that time of day is a crucial contributor to maintaining a healthy body mass index. Amplifying the impact of exercise on both metabolic pathways within skeletal muscle and systemic energy homeostasis can be actualized by properly scheduling your workout regimens around your particular goals.

“On this basis, we cannot say for certain which is best, exercise in the morning or exercise in the evening,” says Treebak. “At this point, we can only conclude that the effects of the two appear to differ, and we certainly have to do more work to determine the potential mechanisms for the beneficial effects of exercise training performed at these two time-points.”

Time of Exercise Specifies the Impact on Muscle Metabolic Pathways and Systemic Energy Homeostasis

The new paper, published in the Journal Cell Metabolism, used mouse models too. Given these rodents adhere to a nocturnal circadian rhythm every find was reversed to gauge its applicability to human trials.

The mice were placed on treadmills at different points of the day. The researchers were able to monitor the gene expressions of the subjects with the help of advanced high-throughput transcriptomic technology. Upon further inspection, it became clear that the mice cells responded differently to energy production and conversion as a result of their chronotypes. 

At night the subjects processed substances more effectively but during the day the rodents burned considerably more calories than they did later in the evening. These metabolic changes were determined to be pretty consistent in crepuscular creatures, which supports the supposition that the inverse will be observable in human models. 

Previously published research has suggested metabolic differences associated with physical activity and circadian rhythms bear the potential to mitigate certain somatic differences.

Exercising regularly at consistent times trains our bodies to properly utilize insulin. 

This is why exercising directly after a meal has been shown to reduce one’s risk for developing heart disease, diabetes in addition to reducing blood sugar levels.

“There appears to be rather significant differences between the effect of exercise performed in the morning and evening, and these differences are probably controlled by the body’s circadian clock,” says co-author Jonas Thue Treebak, an associate professor from the Novo Nordisk Foundation Center for Basic Metabolic Research, in a press release.

The new paper was co-authored by Shogo Sato, Astrid Linde Basse, Milena Schönke, Jonas T. Treebak, Juleen R. Zierath and Paolo Sassone-Corsi

Be sure to read the full report in the Journal Cell Metabolism.