Time limit in two interval training models derived from the futsal intermittent endurance test in brazilian male and female futsal players

This study compared the physiological responses and time limits (TL) in two interval training (IT) models based on peak speed (PSFIET), featuring one change of direction (IT7.5x7.5) and three changes of direction (IT15X15). Fifty-six male (M1; M2) and female (F1; F2) futsal players participating in regional and national futsal leagues were randomly assigned to three different exercise intensities, with each group performing IT7.5x7.5 and IT15X15 at specific intensities (TL1, TL2 and PS100Fiet). The IT7.5x7.5 model involves a run with a 180° change of direction, two accelerations and one deceleration, with featuring 4 min sets and a 3 min break between sets, with work-torest: 1:1. On the other hand, the IT15x15 includes three changes of direction, four accelerations and three decelerations, with four 4 min sets and a 3 min break between sets, maintaining work-to-rest: 1:1 Our results revealed no differences in mean heart rate and maximum heart rate obtained in the Futsal Intermittent Endurance Test (FIET) tests. In addition, our main results showed that the groups that performed TL1 (M1: p =0.018 and F1: p = 0.019) and TLPS100%fiet (p = 0. 014) had lower TL for IT15x15 compared with IT7.5X7.5. Moreover, o IT15x15 at TL2 performed by F2 group, showed higher maximum heart rate value than IT7.5x7.5 (p = 0.002). In conclusion, our results showed that IT with one change of direction allows athletes to have a higher TL when compared to IT with three changes of direction. These findings may be directly related to the increase in muscle demand caused by a greater number of changes of direction, which leads to more accelerations and decelerations, thus generating a reduction in TL.