Effectiveness Of Blood Flow Restriction Training On Aerobic Performance During Cycling Exercise In Healthy Adults.

Abstract

Blood flow restriction (BFR) has emerged as an alternate rehabilitation modality, intending to enhance functional outcomes in various populations. However, there is a lack of research evidence on the efficacy of BFR during aerobic exercise. PURPOSE: To compare aerobic capacity following a cycling protocol with BFR at 60% (BFR-60) versus 80% (BFR-80) occlusion. METHODS: Ten healthy participants (26 ± 3.0 years; 6 males; 4 female) were randomly assigned to either: BFR-60 or BFR-80. Aerobic Capacity was measured at baseline, and three weeks during a sub-maximal stationary cycle ergometer protocol connected to a metabolic analyzer for the assessment of peak oxygen consumption (VO2 peak). Aerobic testing consisted of performing the YMCA protocol which consisted of pedaling at 70 rev/min with a load of 25-watts. Heart Rate (HR) was monitored continuously at the end of the first three minutes and used to determine the load increase. Subjects cycled for 15 minutes at which point a 25-watt increase occurred every 3 minutes until the participant reached one or more of the following criteria: 80% of their predicted HR (T80) using the HR reserve formula, an RER >1.0, or a leveling of the oxygen curve. Given the small sample size and the non-normal data distribution for the variable of T80, a Mann-Whitney and Wilcoxon tests were used to evaluate between and within (time) groups differences, respectively. For the between-group comparison, a composite score for T80 based on the pre-post difference was calculated for both groups. Then this calculated difference was used to compare both groups. Peak VO2 was normally distributed, therefore, 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 between group comparisons of the T80 was not statistically significant. The within group comparison for T80 for the BFR-60 group approached significance (p = 0.08) while the BFR-80 group was not significant (p = 0.89). The within time ANOVA approached significance (p = 0.09) while there were no between group differences (p = 0.99). CONCLUSIONS: Aerobic performance over time was seen to improve primarily in the 60% occlusion BFR group. The small sample size or short intervention duration might have affected the effectiveness of this intervention.