Effectiveness Of Blood Flow Restriction Training On Isokinetic Muscle Strength Of The Quadriceps.

PURPOSE: To examine the effectiveness of blood flow restriction (BFR) training while using two different cuff pressures on the strength of the quadriceps muscle group after three weeks of cycling training for fifteen minutes. METHODS: Ten healthy participants (4 females, 6 males, age 26 ± 3 years) were randomly assigned to one of two groups: BFR with 60% occlusion or BFR with 80% occlusion on their right leg. The training protocol consisted of cycling on a stationary ergometer for 15 minutes at 70 RPM, 25 watts of resistance with the BFR cuff inflated to their assigned occlusion percentage, performed three times a week for three weeks. Bilateral muscle strength of the knee extensors was measured at baseline and at three weeks using an isokinetic dynamometer at speeds of 60, 180, and 300 degrees per second using a standardized knee extension protocol. Given the normally distributed data for torque and work of the knee extensors, a 2 x 2 (group by time) ANOVA was used to perform between and within-group comparisons. Statistical significance was at an alpha of 0.05 for all analyses. RESULTS: The ANOVA revealed no between group differences but statistically significant changes within time for torque at 180 (p < .001) and 300 (p = 0.01) degrees per seconds. Work at 180 and 300 degrees per seconds were also statistically significant (p < .001 and .013, respectively) across time. CONCLUSIONS: It appears to be no differences between the two different BFR occlusion pressures between groups, indicating both occlusion pressures elicit similar gains in quadriceps strength over a three-week period. However, it seems both groups displayed improved torque and work at higher speeds indicating that BFR training provides more benefits in increasing muscular endurance opposed to strength itself.