THE PHYSIOLOGICAL VALIDITY OF CRITICAL SPEED DERIVED FROM A 3-MINUTE ALL-OUT SWIM TEST

Abstract

INTRODUCTION AND AIMS The boundary between heavy and severe exercise domains is one of the most consistent predictors of swimming performance. The gold standard approach to assessing this physiological threshold (numerous 30-minute constant-load trials) is complex and time-consuming, leading practitioners to explore other methodologies, which has left coaches questioning the validity of testing outcomes and reducing testing implementation. The recent proposal of a modified 3-minute all-out swim test has produced reliable estimates of critical speed (CS), however the estimates have not been validated against physiological measures. The aim of this study was to establish the physiological validity of CS derived from the modified 3-minute all-out swim test in elite swimmers. METHODS 16 elite swimmers completed a 3-minute test consisting of 12 maximal 25-m efforts separated by 5s of rest. CS was calculated as the average speed of the slowest two 25-m efforts from the last four completed. To identify MLSS, swimmers completed a 30-minute trial broken into 6 x 5-minute intervals. Blood lactate concentration collected at each interval determined the subsequent interval speed. Over two additional visits, participants completed a 30-minute constant speed trial – at 2% above and 2% below CS to determine the physiology surrounding CS. Statistical analyses were conducted to compare CS and MLSS and determine their association, and to compare physiological measures within the two constant load trials. RESULTS MLSS and CS were not statistically different (p>0.05) and had a strong positive correlation (r=0.98). A physiological steady state was verified in the below CS trial (p>0.05). A physiological steady state was not obtained in the above CS trial (p<0.05). CONCLUSIONS These findings suggest the modified 3-minute all-out swim test as a valid methodology to assess the CS of elite swimmers. Implementation of this methodology could enable critical insight into how athletes are adapting to training and contribute significantly to swimming talent identification.