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Exercise is often recommended as an effective strategy for weight loss. However, a recent animal study at University of Tsukuba revealed that intense exercise sessions can decrease subsequent physical activity levels and body temperature, ultimately contributing to weight gain. This observation may be linked to disruptions in the circadian rhythm of the stress hormone corticosterone and may disturb the synchronous effects of physical activity and body temperature.

Tsukuba, Japan—Exercise provides numerous health benefits, but its effects on weight loss are sometimes less than expected. This phenomenon may be secondary to reduced physical activity following exercise, but the mechanism is not yet fully understood. The stress hormone corticosterone follows a circadian rhythm, being low at bedtime and at its peak upon waking, and it regulates physical and mental activity levels. Therefore, researchers hypothesized that even a single session of high-intensity exercise can disrupt this rhythm, leading to decreased physical activity and heat production and diminishing the weight loss effect.

To test this hypothesis, mice were divided into three groups as follows: high-intensity exercise, moderate-intensity exercise, and rest. The physical activity and core body temperature, which serve as an index of heat production before and after exercise, of the mice were monitored. In the high-intensity exercise group, both physical activity and core body temperature after exercise significantly decreased, despite the absence of changes in food intake, leading to body weight gain. Furthermore, the researchers observed the disruption in the synchrony between physical activity and body temperature. Together, they confirmed a positive correlation that relatively low blood corticosterone levels during wake times were associated with less physical activity.

These findings indicated that a single session of high-intensity exercise can disrupt the circadian rhythm of corticosterone, leading to reduced physical activity and body temperature and body weight gain. This study highlighted the importance of considering not only the calories burned during exercise but also the subsequent activity levels and circadian rhythm when designing exercise regimens for effective weight loss.

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This study was supported by Grant in Aid for Scientific Research (B) ( 22H03478: Rep. T.M.), Grant in Aid for Scientific Research (C) (22K11528: Rep. T.N.), Grant in Aid for Research Activity Start up (22K21199: Rep. D.F.), Grant in Aid for Early Career Scientists (24K20595: Rep. D.F.) by JSPS KAKENHI, and by Japan Science and Technology Agency (JST) (JPMJFR205M: Rep. T.M).

Original Paper

Title of original paper:

Acute Vigorous Exercise Decreases Subsequent Non-Exercise Physical Activity and Body Temperature Linked to Weight Gain

Journal:

Medicine & Science in Sports & Exercise

DOI:

10.1249/MSS.0000000000003487

Correspondence

Assistant Professor MATSUI Takashi
Researcher FUNABASHI Daisuke
Institute of Health and Sport Sciences, University of Tsukuba

Associate Professor NISHIJIMA Takeshi
Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University

Related Link

Institute of Health and Sport Sciences