Here’s your excuse for not working today.
A single session of high-intensity exercise can disrupt the body’s main stress hormone, which can lead to decreased activity, lower body temperature, and weight gain after the workout. A new study of mice has been found.
Researchers at the University of Tsukuba in Japan divided the mice into three groups: vigorous exercise, moderate exercise, and rest. The exercise groups underwent a 30-minute treadmill session.
Only the high-exercise group showed a reduction in body temperature and post-exercise, leading to weight gain the next day – despite no changes in food intake.
Mice who exercised very hard were 30 percent less active in the 24 hours after exercise compared to days when they didn’t exercise, researchers said, compensating by burning more energy on the treadmill.
Study author Takashi Matsui said: “Real-world experiences of people who feel too tired to move after intense exercise believe that our study’s findings can be replicated in humans.” He told New Scientist in April..
The findings were published last week in the journal Medicine and science in sports and exercise.
The researchers pointed the finger at insufficient levels of corticosteroids when starting the day.
Cortisol is the major stress hormone in humans and corticosterone in many animals such as laboratory rats. Cortisol levels are highest in the morning and decrease throughout the day and decrease at bedtime.
The researchers noted that lower cortisol levels before awakening were associated with less physical activity.
The study’s authors plan to investigate whether more intense exercise leads to weight gain in mice.
In the meantime, they hope that fitness trainers who design workouts will consider exercise intensity along with calories burned.
Matsui told New Scientist, “It’s counterproductive to overextend yourself to the point of not doing any exercise afterward.” “Therefore, the advice for people who want to lose weight is to recognize the importance of not exercising and to moderate exercise to maintain overall daily activity.”
But one metabolomist expressed doubts about the guidelines.
“I’m not sure we can attribute these results to moderate activity over vigorous activity,” Herman Pontzer, a professor of evolutionary anthropology and global health at Duke University, told New Scientist. “It’s not clear that this particular effect will occur in humans.”