Sensitivity of the yo-yo intermittent recovery test and cardiac autonomic responses to training in Futsal players

Purpose: This study examined the sensitivity of maximal (Yo-Yo Intermittent Recovery [IR] 1 and 2) and submaximal (5′-5′) tests to identify training adaptations in futsal players along with the suitability of heart-rate (HR) and HR-variability (HRV) measures to identify these adaptations. Methods: Eleven male professional futsal players were assessed before (pretraining) and after (posttraining) a 5-wk period. Assessments included 5′-5′ and Yo-Yo IR1 and IR2 performances and HR and HRV at rest and during the IR and 5′-5′ tests. Magnitude-based-inference analyses examined the differences between pre- and posttraining, while relationships between changes in variables were determined via correlation. Results: Posttraining, Yo-Yo IR1 performance likely increased while Yo-Yo IR2 performance almost certainly increased. Submaximal HR during the Yo-Yo IR1 and Yo-Yo IR2 almost certainly and likely, respectively, decreased with training. HR during the 5′-5′ was very likely decreased, while HRV at rest and during the 5′-5′ was likely increased after training. Changes in both Yo-Yo IR performances were negatively correlated with changes in HR during the Yo-Yo IR1 test and positively correlated with the change in HRV during the 5′-5′. Conclusions: The current study has identified the Yo-Yo IR2 as more responsive for monitoring training-induced changes of futsal players than the Yo-Yo IR1. Changes in submaximal HR during the Yo-Yo IR and HRV during the 5′-5′ were highly sensitive to changes in maximal performance and are recommended for monitoring training. The 5′-5′ was recommended as a time-efficient method to assess training adaptations for futsal players.