PROBLEM: The effects of resistance exercise with blood flow restriction (BFR) on autonomic modulation are unclear. Therefore, the purpose of the present study was to evaluate autonomic modulation after resistance exercise with and without BFR in resistance-trained men. METHODS: Sixteen men volunteered for the study. Autonomic modulation was assessed at rest, 15 (Rec1), and 25 (Rec2) minutes after three different conditions. The low-intensity bench press with BFR (LI-BFR) consisted of 4 sets of 30, 15, 15, and 15 repetitions at 30% 1-repetition maximum (1RM). The high-intensity bench press (HI) consisted of 4 sets of 8 repetitions at 70%1RM, and a supine rest control (CON). Autonomic modulation was expressed as natural logarithm (Ln), high-frequency power (LnHF), low-frequency power (LnLF), and sympathovagal balance (LnLF/LnHF ratio). RESULTS: There was a significant condition by time interaction for LnHF (LI-BFR: Rest: 7.3±1.1ms2, Rec1: 5.5±1.2ms2, Rec2: 6.6±1.5ms2; HI: Rest: 7.4±1.2ms2; Rec1: 5.9±1.4ms2, Rec2: 6.5±1.5ms2; CON: Rest: 7.5±1.1ms2, Rec1: 7.5±1.8ms2, Rec2: 7.4±1.3ms2, Rec1: 5.9±0.9ms2, Rec2: 6.5±1.2ms2; HI: Rest: 7.3±1.1ms2; Rec1: 6.4±0.8ms2, Rec2: 6.6±1.2ms2; CON: Rest: 7.1±1.0 ms2, Rec1: 7.1±1.8 ms2, Rec2: 7.1±1.0 ms2. CONCLUSION: These data suggest that LI-BFR and HI similarly alter autonomic modulation for at least 30 minutes.
Dr. J. Derek Kingsley
The purpose of the present study was to evaluate autonomic modulation after bench press with and without blood flow restriction (BFR). Sixteen men had their autonomic modulation assessed at rest, 15 (Rec1), and 25 (Rec2) minutes after three different conditions: low-intensity exercise with BFR (LI-BFR), high-intensity exercise (HI), and a control (CON). Autonomic modulation consisted of vagal tone, sympathetic modulation and sympathovagal balance. There was a significant condition by time interaction for vagal tone such that it was reduced at Rec1 and Rec2 after LI-BFR and HI compared to Rest and CON. There was a main effect of time for sympathovagal balance such that it was increased at Rec1 and Rec2 compared to Rest. These data suggest that LI-BFR and HI similarly alter autonomic modulation.