Skip to content

Morning Gym-Goers Burn More Calories: Study

The body's ability to regulate its energy and maximize the health advantages of exercise appears to be influenced by timing

Morning gym-goers reap more reward – by burning more calories, suggests a new study.

Mice have a higher metabolism if they exercise early in the day – and scientists say that is reflected in humans. Biological processes work differently depending on the time of day, due to each cell’s circadian rhythm.

Researchers at Karolinska Institutet in Sweden set out to discover the impact on our workouts. At two points in the day, experts set mice on a high-intensity workout and studied their adipose tissue afterwards.

A jogger runs in Preston Park, in Brighton, south of England, at sunrise on February 14, 2023. Due to the circadian cycle of each cell, biological processes fluctuate depending on the time of day, which is why exercising in the day may be more advantageous. PHOTO BY GLYN KIRK/AFP/GETTY IMAGES

Joined by a team from University of Copenhagen, Denmark, the researchers marked an early active phase and early rest phase, corresponding to late morning and late evening gym session in humans.

They looked at which genes were active in adipose tissue, otherwise known as body fat, and discovered those involved with boosting the metabolism were more abundant in the morning slot – regardless of how much food they ate.

Morning work-out genes broke down fat by producing heat and mitochondria in the adipose tissue.

Professor Juleen Zierath, of Karolinska Institutet, said: “Our results suggest that late morning exercise could be more effective than late evening exercise in terms of boosting the metabolism and the burning of fat, and if this is the case, they could prove of value to people who are overweight.

A man seen running on Westminster Bridge with a view of Big Ben and the Houses of Parliament on a sunny day in London. The appropriate time appears to be crucial for the body’s energy balance and for maximizing the health advantages of exercise, but additional research is required, a new study reveals. PHOTO BY STEVE TAYLOR/SOPA/GETTY IMAGES

“The right timing seems to be important to the body’s energy balance and to improving the health benefits of exercise, but more studies are needed to draw any reliable conclusions about the relevance of our findings to humans.”

The physiology and metabolism of mice have long been used as a model for human physiology. However, the researchers say that their comparison, published in the Proceedings of the National Academy of Sciences is limited by the fact mice are nocturnal.

Produced in association with SWNS Talker.

Recommended from our partners