We aimed to investigate whether a Blood Flow Restriction Training (BFR) prior to a High Intensity Interval Training (HIIT) leads to a higher increase in physical performance than a sole HIIT.
24 male participants (18 to 30 years) were randomly assigned to a BFR+HIIT or HIIT group which performed 3 times per week over 4 weeks a HIIT on bicycle-ergometers. Prior to each training session of the HIIT, both groups carried out 4 sets of deep squats without additional load but the BFR+HIIT group performed this exercise under BFR conditions. Immediately before and after the intervention period, the endurance capacity and strength capacity was assessed by a spiroergometry (parameter: maximal power, maximal oxygen consumption per kilogram body weight [VO2max/kg]) and a maximal strength test for the legs [1RM] as well as the Counter Movement Jump [CMJ]. The Growth Hormone (GH) and Insulin-like Growth Factor 1 (IGF-1) were measured prior to and after the first and last intervention. Blood lactate concentrations [La] were assessed immediately before and after deep squats as well as after the HIIT during the sixth training session.
The maximal power increased significantly in both groups (BFR+HIIT: + 9.5%, p < 0.001; HIIT: + 4.5%, p = 0.038) but to a higher extent in the BFR+HIIT group (interaction effect: F = 4.80, p = 0.039, ηp2 = 0.179). The VO2max/kg did not change due to the intervention of the BFR+HIIT and HIIT group. Regarding the 1RM and CMJ, a significant improvement in 1RM (p = 0.005) was observed only in the HIIT group. Both, GH and IGF-1 increased significantly immediately after the interventions, but without differences between groups (no interaction effect). La increased during the intervention in a comparable manner among both groups.
The combined intervention efficiently improves the maximal power in context of endurance capacity. Here, the underlying mechanisms have to be clarified in future investigations.