Introduction: Exercise-induced muscle damage (EIMD) leads to increases in intramuscular proteins observed in the blood stream and delayed onset of muscle soreness, but crucial for athletes are the decrements in muscle performance observed. Previous research has demonstrated that carbohydrate–protein supplements limit these decrements; however, they have primarily used isokinetic dynamometry, which has limited applicability to dynamic sport settings. Therefore, the aim of this study was to investigate the effects of a carbohydrate–protein milk supplement consumed after muscle-damaging exercise on performance tests specific to field-based team sports.
Methods: Two independent groups of seven males consumed either 500 mL of milk or a control immediately after muscle-damaging exercise. Passive and active delayed onset of muscle soreness, creatine kinase, myoglobin, countermovement jump height, reactive strength index, 15-m sprint, and agility time were assessed before and 24, 48, and 72 h after EIMD. The Loughborough Intermittent Shuttle Test was also performed before and 48 h after EIMD.
Results: At 48 h, milk had a possible benefit for limiting increases in 10-m sprint time and a likely benefit of attenuating increases in mean 15-m sprint time during the Loughborough Intermittent Shuttle Test. At 72 h, milk had a possible benefit for limiting increases in 15-m sprint time and a likely benefit for the attenuation of increases in agility time. All other effects for measured variables were unclear.
Conclusion: The consumption of milk limits decrements in one-off sprinting and agility performance and the ability to perform repeated sprints during the physiological simulation of field-based team sports.
Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle Upon Tyne, UNITED KINGDOM
Address for Correspondence: Emma Cockburn, Ph.D., Department of Sport Development, Northumberland Building, Northumbria University, Newcastle Upon Tyne, NE1 8ST, UK; E-mail: firstname.lastname@example.org.
Submitted for publication September 2012.
Accepted for publication January 2013.