Edwards, A.M., Mann, M., Marfell-Jones, M., Noakes, T.D., Rankin, D., and Shillington, D. (2006) The influence of moderate dehydration on soccer-related performance: a comparison of fluid intake strategies consistent with match play opportunities. In: Papers from New Zealand Sports Medicine and Science Conference. p. 40. From: New Zealand Sports Medicine and Science Conference, 16-18 November 2006, Wellington, New Zealand.

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Abstract

Introduction: Only a limited amount of inlormation is currently available on the thermoregulatory responses of soccer players during competitive match-play and particularly thc extent to which dehydration might impact on performance relatcd fitness. Despite obvious difficulties in directly measuring decrements in soccer match performance, few studies have utilised an experimental model incorporating outdoor match-play. This is surprising, as heat dissipation via convective cooling is impaired in willdstill em1ronments such as those normally encountered in indoor laboratory settings.

Methodology: Eleven moderately active male soccer players (age: 24.4 ±3 years, body mass: 74.03 ±10.54 kg, height: 1.75 ±0.07 m, VO, peak: 50.91 ±3.95 ml kg min) volunteered to participate in the study. Each subject performed a 90-min soccer simulation protocol (45-min laboratory cycle & 45-min ourdoor soccer match) on three separate occasions while undertaking differential water replacement strategies: 1) fluid-intake (FL)2) mouth rinse only (MR)3) no-fluid (NF). Core temperature (Ct) and heart rates were measured at 10-min intervals throughout the protocol and pre- and post-test assessments were made of plasma and urine osmolalities (Posm &; Uosm), body composition, sweat rates, and heat storage. Post-protocol firness in each of the expetimental conditions was evaluated by tests of sport-specific fitness and mental concentration.

Results: The only condition-dependent difference during the 90-min protocol was a significantly elevated Cy in the NF condition (P<0.05). Pre- to post-test Posm was significantly elevated in both MR and NF (P<O.O1), but Uosm was only significantly elevated in the post-test sample (NF) when log transformed (P<0.05). Post-test mental concentration was not different across the 3 conditions but the sport specific test performance was significantly negatively influenced in both NF and MR compared with FL (P<O.O1). Post-test evaluation of RPE indicated that the NF condition was perceived to be the most challenging (P<0.05) but there were no differences in heat storage or sweat rates.

Conclusions: The performance of a validated soccer-specific fitness test following the 90-min soccer simulation protocol was significantly impaired in the NF condition. It is possible that this could be attributable to either an increased thermal strain as a consequence of moderate dehydration, or negative psychological associations with an increased desire to drink. The results of this study appear to suggest a physiological mechanism is likely but further studies are required in which thirst is fully satisfied.

Item ID:	19046
Item Type:	Conference Item (Abstract / Summary)
ISBN:	978-0-909020-07-1
Related URLs:	Organisation
Date Deposited:	23 Nov 2011 01:59
FoR Codes:	11 MEDICAL AND HEALTH SCIENCES > 1106 Human Movement and Sports Science > 110604 Sports Medicine @ 60% 11 MEDICAL AND HEALTH SCIENCES > 1106 Human Movement and Sports Science > 110602 Exercise Physiology @ 40%
SEO Codes:	92 HEALTH > 9299 Other Health > 929999 Health not elsewhere classified @ 100%
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