The effects of high-intensity functional training on muscle damage and recovery capacity in trained individuals

Abstract

Objective: High-Intensity Functional Training (HIFT) is nowadays widely used due to low time demand and efficiency to improve performance and health. The dynamics of recovery of muscle damage and physical fitness after a HIFT in individuals with different fitness status provide a practical information for coaches and practitioners. Therefore, the aim of this study was to verify the muscle damage and performance recovery responses after an acute HIFT session in healthy young men with different fitness status.Method: Sixteen recreationally trained participants (age: 23.4 ± 2.4 y; body mass index: 24.6 ± 2.4 kg·m-2; 1RM back squat: 120.1 ± 19.9 kg) were divided into two groups according to their maximum strength (higher-trained [HT] and lower-trained group [LT]), and performed a single HIFT session. Muscle damage (creatine kinase [CK] and lactate dehydrogenase [LDH]) and physical fitness tests (strength, power, and oxygen consumption) were analyzed before, immediately after, 24h and 48h after the HIFT session. The internal training load for both groups was equalized using the Rating of Perceived Exertion method (RPE) and the percentage 1 repetition maximum (1RM).Results: Biochemical markers and performance indicators showed that both groups suffered exercise-induced muscle damage. There was a trend towards faster muscle damage recovery in HT group.Conclusions: HT group showed higher muscle damage recovery compared to the LT group. A longer recovery time to complete muscle recovery might be expected in the LT group.