Higher Activity Energy Expenditure And Lower Resting Energy Expenditure Among Healthy Female Athletes

Abstract

Among non-athletes, total energy expenditure (TEE) and physical activity energy expenditure (PAEE) increases over the low and middle range of physical activity, but resting energy expenditure (REE) does not (Pontzer, 2016). However, compensatory metabolic adaptation is found among highly trained athletes (Silva, 2017). PURPOSE: To clarify the relationship between TEE and its components over a wide range of physical activity levels (PAL) among healthy female athletes. METHODS: Eighty-five healthy female college athletes (short, middle and long distance runners, jumpers, throwers, walkers, swimmers, rhythmic sportive gymnasts, judo players, and lacrosse players) were evaluated during the training season. TEE and REE were assessed by the doubly labelled water method and respirometry, respectively. Total energy intake (TEI) was assessed using 7-day dietary record. PAEE was determined as TEE-0.1(TEE)-REE, and PAL was determines as TEE/REE. Among them, 41 athletes were measured for training induced energy expenditure (TIEE) using heart-rate monitoring. Adjusted TEE, REE, TIEE, and TEI were calculated using the residuals of regression analysis to eliminate the effects of fat free mass, fat mass, age and height. Estimated REE (eREE) was calculated using an equation used in Taguchi’s study (2011). RESULTS: Adjusted TEE, PAEE and TIEE were significantly positively correlated with PAL (r=0.636, 0.848, and 0.425, p<0.001, p<0.001, and p=0.001). Adjusted REE and the difference between REE and eREE were significantly negatively correlated with PAL (r=-0.531 and -0.468, p<0.001 for both). However, adjusted TEI did not correlate significantly with PAL (r=0.198, p=0.069). CONCLUSIONS: Both higher energy expenditure related to physical activity and/or training and lower REE lead to higher PAL among female athletes. Lowered REE may be caused by insufficient energy intake in relation to high energy expenditure.