Within-Day Energy Deficiency and Metabolic Perturbation in Male Endurance Athletes.

Autor:	Torstveit, Monica Klungland, Fahrenholtz, Ida, Stenqvist, Thomas B., Sylta, Øystein, Melin, Anna
Předmět:	NUTRITION disorders BODY composition ENDOCRINE system physiology BASAL metabolism BIOMARKERS BLOOD plasma BLOOD sugar BLOOD volume CYCLING ENDURANCE sports ENERGY metabolism FASTING HYDROCORTISONE INGESTION METABOLISM TESTOSTERONE TRIATHLON TRIIODOTHYRONINE SPORTS events LONG-distance running MALE athletes PHOTON absorptiometry DISEASE risk factors
Zdroj:	International Journal of Sport Nutrition & Exercise Metabolism; Jul2018, Vol. 28 Issue 4, p419-427, 9p, 1 Diagram, 5 Charts
Abstrakt:	Endurance athletes are at increased risk of relative energy deficiency associated with metabolic perturbation and impaired health. We aimed to estimate and compare within-day energy balance in male athletes with suppressed and normal resting metabolic rate (RMR) and explore whether within-day energy deficiency is associated with endocrine markers of energy deficiency. A total of 31 male cyclists, triathletes, and long-distance runners recruited from regional competitive sports clubs were included. The protocol comprised measurements of RMR by ventilated hood and energy intake and energy expenditure to predict RMRratio (measured RMR/predicted RMR), energy availability, 24-hr energy balance and within-day energy balance in 1-hr intervals, assessment of body composition by dual-energy X-ray absorptiometry, and blood plasma analysis. Subjects were categorized as having suppressed (RMRratio < 0.90, n = 20) or normal (RMRratio > 0.90, n = 11) RMR. Despite there being no observed differences in 24-hr energy balance or energy availability between the groups, subjects with suppressed RMR spent more time in an energy deficit exceeding 400 kcal (20.9 [18.8–21.8] hr vs. 10.8 [2.5–16.4], p =.023) and had larger single-hour energy deficits compared with subjects with normal RMR (3,265 ± 1,963 kcal vs. −1,340 ± 2,439, p =.023). Larger single-hour energy deficits were associated with higher cortisol levels (r = −.499, p =.004) and a lower testosterone:cortisol ratio (r =.431, p =.015), but no associations with triiodothyronine or fasting blood glucose were observed. In conclusion, within-day energy deficiency was associated with suppressed RMR and catabolic markers in male endurance athletes. [ABSTRACT FROM AUTHOR]
Databáze:	Complementary Index
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