Open water swimming in elite triathletes: physiological and biomechanical determinants

Abstract

This study aimed (i) to analyze the 1500 m open water swimming performance, (ii) to examine the associations between physiological and biomechanical variables with swimming performance, and (iii) to determine which variables can predict swimming performance in triathletes. Fourteen elite triathletes (23.4±3.8y) performed a 1500m test in open water swimming conditions. Swimming performance was assessed using World Aquatics Points Scoring, and data were obtained from the 1500 m open water swimming test. Heart rate, end-exercise oxygen uptake (EEVO˙ 2) and blood lactate concentrations were measured. The initial 250m of the 1500m swimming test presented the highest values of biomechanical variables in males (i. e. swimming speed, stroke rate (SR), length (SL), index (SI)). A decrease in SL was observed in the last 250m in both sexes. Positive association were found between EEVO˙ 2 (r = 0.513; p = 0.030), swimming speed (r = 0.873; p < 0.001) and SI (r=0.704; p=0.002) with swimming performance. In contrast, time constant of the oxygen uptake (r = −0.500; p = 0.034) and buoy-turn times (r = −0.525; p = 0.027) were negatively associated with performance. SI was the main predictor (R2 = 0.495) of open water swimming performance in triathletes. In conclusion, triathletes and coaches must conduct open water training sessions to maximize SI (i. e. swimming efficiency).