Low intensity rowing with blood flow restriction over 5 weeks increases V̇O2max in elite rowers: A randomized controlled trial

OBJECTIVES: The present randomized controlled intervention study examined the effects of practical blood flow restriction (pBFR) on maximal oxygen uptake (V̇O2max) during low intensity rowing.

DESIGN: Thirty-one elite rowers were either assigned to the intervention (INT) or control (CON) group, using the minimization method (Strata: Gender, Age, Height, V̇O2max).

METHOD: While INT (n=16; 4 female, 12 male, 21.9±3.2 years, 180.4±8.7cm, 73.6±10.9kg, V̇O2max: 63.0±7.9ml/min/kg) used pBFR during boat- and indoor-rowing training, CON (n=15, 4 female, 11 male, 21.7±3.7 years, 180.7±8.1cm, 72.5±12.1kg, V̇O2max: 63.2±8.5ml/min/kg) completed the identical training without pBFR. pBFR of the lower limb was applied via customized elastic wraps. Training took place three times a week over 5 weeks (accumulated net pBFR: 60min/week; occlusion per session: 2-times 10min/session) and was used exclusively at low intensities (<2mmol/L). A spiroergometric ramp test (V̇O2max; 30-40W/min increase) on rowing-ergometer and one-repetition maximum test of the squat exercise (SQ1RM) was employed to assess endurance and strength capacity.

RESULTS: Significant group×time interactions (ηp²=0.26) in favor of INT were found for V̇O2max (+9.1±6.2%, Effect Size=1.3) compared to CON (+2.5±6.1%, ES=0.3). SQ1RM (ηp²=0.01) was not affected by the pBFR intervention.

CONCLUSIONS: This study revealed that 15 sessions of pBFR application with a cumulative total pBFR load of 5h over a 5 weeks macrocycle remarkably increased V̇O2max. Thus, pBFR might serve as a promising means to improve aerobic capacity in highly trained elite rowers.