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Researchers at University of Tsukuba have found that female endurance runners who run longer distances expend more energy during exercise, whereas their total daily energy expenditure is not associated with running distance. These findings suggest that the distribution of daily energy expenditure across different activities and physiological processes varies with training volume.

Tsukuba, Japan—Generally, total energy expenditure is expected to be higher in individuals with greater physical activity. However, the constrained total energy expenditure model suggests that greater energy expenditure during exercise may be offset by lower energy expenditure during other activities or physiological processes, thereby maintaining total energy expenditure within a relatively limited range. It is unclear whether similar patterns occur in athletes engaged in long-term endurance training. Furthermore, although amenorrhea is sometimes observed among female runners, it is not well understood whether the components of total energy expenditure differ between amenorrhoeic and non-amenorrhoeic runners. Therefore, this study compared total energy expenditure and its components in female runners with and without amenorrhea and assessed their associations with weekly running distance.

The study found that total energy expenditure and its components were similar in amenorrhoeic and non-amenorrhoeic runners. Furthermore, although longer weekly running distance was associated with greater energy expenditure during exercise, total energy expenditure was not associated with running distance. Runners covering longer distances tended to expend less energy during non-exercise activities, as reflected by lower non-exercise activity thermogenesis . Resting and sleeping metabolic rates were also negatively associated with running distance, although these associations weakened after adjusting for fat-free and fat mass. Collectively, these findings suggest that greater training volumes may be accompanied by differences in energy expenditure distribution across exercise, daily activities, and resting metabolism. Similar patterns were observed in both groups, although further research is required to clarify whether menstrual status modifies these associations and whether these differences are beneficial or reflect an early sign of energy deficiency. Because this was a cross-sectional study, longitudinal studies are necessary to establish causality.

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This work was supported by the University of Tsukuba Basic Research Support Program Type S to H.S.; the JSPS KAKEN to A.U. (22J11154, 25KJ0427), H.S. (23H03279, 23KK0177, 26K02782).

Original Paper

Title of original paper:

Running Distance Is Associated With Components of Total Energy Expenditure in Amenorrhoeic and Non-Amenorrhoeic Endurance Runners

Journal:

Scandinavian Journal of Medicine & Science in Sports

DOI:

10.1111/sms.70362

Correspondence

Assistant Professor SAGAYAMA Hiroyuki
Institute of Health and Sport Sciences, University of Tsukuba

Researcher UCHIZAWA Akiko
Department of Sports Sciences, Japan Institute of Sports Sciences
JSPS Research Fellow, Japan Society for the Promotion of Science

Related Link

Institute of Health and Sport Sciences