RESUMEN
BACKGROUND: Repeated sprint ability (RSA) in women's soccer is crucial to ensure high level of performance during the game. The aim of this study is to investigate the acute effects of two different initial heart rates intensities on fatigue when testing the RSA. METHODS: Since there are many kinds of pre-match warming-ups, the heart rate reached at the end of two different warm-up protocols (~90 vs. ≈60% HRmax) as an indicator of internal load has been selected and the respective RSA performances were compared. RSA tests were performed by 19 elite women soccer players (age: 22.5±3.3 years, height 163.9±7.3 cm, body mass 54.3±6.4 kg, BMI 20.6±1.5 kg/m2) with two sets of ten shuttle-sprints (15+15 m) with a 1:3 exercise to rest ratio, in different days (randomized order) with different initial HR% (60% and 90% HRmax). In order to compare the different sprint performances a Fatigue Index (FI%) was computed; the blood lactate concentrations (BLa-) were measured before and after testing, to compare metabolic energy. RESULTS: Significant differences among trials within each set (P<0.01) were found, as evidence of fatigue. Differences between sets were not found, (Factorial ANOVA 2x10; P>0.05). Although the BLa- after warm-up was higher between 90% vs. 60% HRmax (P<0.05), at the completion of RSA tests (after 3 minutes) the differences were considerably low and not significant (P>0.05). CONCLUSIONS: This study shows that, contrary to male soccer, the initial heart rates, induced by different modes of warming-up, do not affect the overall performance while testing RSA in women's soccer players.