Animal study finds that morning exercise improves metabolic response, while night exercise increases energy expenditure

The circadian rhythm is your body’s internal process that follows a daily cycle. This rhythm typically responds to light levels in an individual’s environment, which helps regulate the sleep-wake cycle. Maintaining a consistent circadian rhythm is essential to overall health – chronic disruption of your regular sleep schedule can have adverse health consequences. Now, recent research has found new ways for circadian rhythm to affect your health.

A study published in the journal Cell Metabolism found that a healthy circadian rhythm and the time of day can make an impact on how aerobic exercises affect your metabolism. The study suggests that a morning exercise session can make it easier for muscle cells to metabolize sugar and fat, while an evening exercise session can give you an overall boost to metabolism for a longer duration of time.

“There appear 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. Morning exercise initiates gene programs in the muscle cells, making them more effective and better capable of metabolizing sugar and fat. Evening exercise, on the other hand, increases whole-body energy expenditure for an extended period of time,” said Jonas Thue Treebak from the Novo Nordisk Foundation for Basic Metabolic Research.

Like night and day

Researchers from the University of Copenhagen – in collaboration with the University of California Irvine – looked into understanding the impact of exercise performed at varying times of the day. To test their theories, Treebak and his colleagues had a group of rodents perform exercises at the start and at the end of the day. Afterward, they analyzed the effects of the exercise sessions on the rodents’ muscle cells.

Using high-throughput transcriptomic and metabolomic approaches, the researchers identified very distinct responses of metabolic oscillations that characterize exercise performed in either day or night. Notably, the researchers discovered that a protein called hypoxia-inducible factor 1-alpha (HIF1-alfa), which is responsible for regulating the body’s circadian clock, was involved in these mechanisms. The team explained that this particular protein is selectively activated when you exercise, depending on the time of day. This selective activation results in the usage of alternative energy resources, adaptation of energy expenditure and carbohydrate exhaustion. (Related: Fitness and your circadian rhythm: Is a late-night jog better than an early morning walk?)

Their findings showed that exercising early in the morning can boost the muscle cells’ ability to metabolize fat and sugars – a finding that may spark intrigue in researchers focusing on people with Type 2 diabetes and severe obesity.

On the other end of the spectrum, exercising in the evening can increase your body’s energy expenditure in the hours after a good, long workout. This means that the researchers cannot confidently conclude that doing exercise in the morning is significantly better than doing it in the evening.

“On this basis we cannot say for certain which is best, exercise in the morning or exercise in the evening. 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. We are eager to extend these studies to humans to identify if timed exercise can be used as a treatment strategy for people with metabolic diseases,” Treebak explains.

Whether you decide to go out for a morning jog or save that for a later part of the day, exercise can ultimately provide plenty of health benefits if performed on a regular basis. FightObesity.news has everything you need to know about the health benefits of working out and other natural means of improving your overall health.

Sources include:

SleepFoundation.org

ScienceDaily.com

Cell.com