Basal Serum Cortisol and Testosterone/Cortisol Ratio Are Related to Rate of Na+ Lost During Exercise in Elite Soccer Players
in International Journal of Sport Nutrition and Exercise MetabolismClick name to view affiliation
During exercise, the human body maintains optimal body temperature through thermoregulatory sweating, which implies the loss of water, sodium (Na+), and other electrolytes. Sweat rate and sweat Na+ concentration show high interindividual variability, even in individuals exercising under similar conditions. Testosterone and cortisol may regulate sweat Na+ loss by modifying the expression/activity of the cystic fibrosis transmembrane conductance regulator. This has not been tested. As a first approximation, the authors aimed to determine whether basal serum concentrations of testosterone or cortisol, or the testosterone/cortisol ratio relate to sweat Na+ loss during exercise. A total of 22 male elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise (basal). Sweat samples were collected during a training session, and sweat Na+ concentration was determined. The basal serum concentrations of testosterone and cortisol and their ratio were (mean [SD]) 13.6 (3.3) pg/ml, 228.9 (41.4) ng/ml, and 0.06 (0.02), respectively. During exercise, the rate of Na+ loss was related to cortisol (r = .43; p < .05) and to the testosterone/cortisol ratio (r = −.46; p < .01), independently of the sweating rate. The results suggest that cortisol and the testosterone/cortisol ratio may influence Na+ loss during exercise. It is unknown whether this regulation depends on the cystic fibrosis transmembrane conductance regulator.
Castro-Sepulveda, Cancino, Jannas-Vela, and Zbinden-Foncea are with the Laboratorio de Ciencias del Ejercicio, Escuela de Kinesiologia, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile. Fernández-Verdejo is with the Departamento de Ciencias de la Salud, Carrera de Nutrición y Dietética, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. Pérez-Luco is with the Carrera Preparador Fisico, Centro de Formacion Tecnica Santo Tomas, Santiago, Chile. Ramirez-Campillo is with the Laboratory of Human Performance, Quality of Life and Wellness Research Group, Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno, Chile. Del Coso is with the Laboratorio de Fisiología del Ejercicio, Universidad Camilo José Cela, Madrid, Spain. Zbinden-Foncea is also with the Centro de Salud Deportiva, Clínica Santa Maria, Santiago, Chile.
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