Influence of moderate dehydration on soccer performance: Physiological responses to 45 min of outdoor match-play and the immediate subsequent performance of sport-specific and mental concentration tests
British Journal of Sports Medicine
Department of Human Performance, Faculty of Health Science Technology, UCOL Institute of Technology, Palmerston North, New Zealand; Leeds Metropolitan University, Carnegie Research Institute, Leeds, United Kingdom; UCOL Institute of Technology, Palmerston North, New Zealand; Department of Human Biology, University of Cape Town, Cape Town, South Africa
Objective: To determine whether moderate water loss (∼1.5-2% of body mass (BM)) represents a significant impairment to soccer match-play and the related fitness variables. Methods: 11 moderately active male soccer players (mean (SD) age 24.4 (3) years, BM 74.03 (10.5) kg, peak oxygen consumption 50.91 (4.0) ml/kg/min) volunteered to participate. The experimental procedure comprised: (1) a 45 min pre-match period of cycle ergometry exercise (90% of individual ventilatory threshold); (2) the completion of a 45 min soccer match; and (3) the immediate post-match performance of sport-specific and mental concentration tests. The subjects completed the procedure on three occasions each in a different experimental condition (fluid intake (FL), no fluid (NF) and mouth rinse (MR)) in an individually randomised order. Core temperature (T c), heart rates, plasma and urine osmolalities, BM, sweat rates and heat storage were all measured. Results: The only condition-dependent difference during the match-play element of the protocol was a significantly increased Tc in the NF condition compared with the FL condition (39.28°C (0.35°C) and 38.8°C (0.47°C), respectively; p<0.05). The immediate post-match performance of a sport-specific fitness test was significantly impaired where FL had been denied (p<0.01). The post-test evaluation of rating of perceived exertion and thirst indicated that the NF condition was perceived to be the most challenging (p<0.05). Conclusions: The condition-dependent differences in match-play and post-match tests demonstrate that moderate dehydration is detrimental to soccer performance. However, it remains unclear whether this could be attributable to water loss in itself or the negative psychological associations derived from a greater perception of effort in that condition.
adult; article; body mass; controlled study; core temperature; dehydration; dynamic exercise; exercise physiology; fitness; fluid intake; heart rate; human; human experiment; male; mental concentration; plasma osmolality; psychological aspect; sporting event; sweating; thermoregulation; thirst; urine osmolality; water loss; Adult; Attention; Body Temperature; Body Weight; Cross-Over Studies; Drinking; Exercise; Heart Rate; Humans; Male; Osmolar Concentration; Plasma; Soccer; Task Performance and Analysis; Time Factors; Urine; Water Loss, Insensible