Physiological, perceptual responses, and strategy differences in age-group swimmers between heats and semi-finals in the 400 metres freestyle event

Abstract

ABSTRACT Swimmers use different strategies in competition to proceed from heats to semi-finals and finals. This study aimed to analyse the physiological (heart rate [HR]; blood lactate [BLa]) and perceptual responses (rating of perceived exertion [RPE]), time-performances (T), and strategy differences in age-group swimmers in the 400 m Freestyle swim between heats and semi-finals during a competition. Twenty-Two male swimmers volunteered to participate in this study. Only thirteen out of the sixteen qualified semi-finalists (age 16.8 ± 0.6 years) were considered into data analysis. Significant differences within and between groups were identified for T400, HR, RPE and BLa (p < 0.001). Compared to heats, Top 8 swimmers improved their performance by 7.68% with an increased value of HR (17.24%), RPE (49.41%) and BLa (98.7%), whereas the remaining semi-finalists improved their timings by only 2.51% and with an increased value of HR (7.38%), RPE (23.26%) and BLa (14.14%). These results suggested that Top 8 swimmers adopted a slower swimming speed during the heats but made more effort during the semi-finals. This could be a strategy to save energy in order to perform their best during the semi-finals and be at the top of the standings to qualify for the final.