The effect of aerobic exercise combined with blood flow restriction on physical performance in pre-frail elderly

This study aimed to compare the effect of aerobic exercise combined with BFR and aerobic exercise only on physical performance in pre-frail elderly.

Seventeen pre-frail (Fried frailty phenotype present 1 or 2 criteria) elderly (≥ 65 y/o) were randomized into two groups, receiving aerobic exercise combined with BFR (BFR group) and only aerobic exercise (CON group) respectively. Both groups received 18 sessions of moderate-intensity (50-70% heart rate reserve) aerobic exercise (3 times/week for 6 weeks), including step training, march in place and treadmill walking training. An additional 50% of limb occlusion pressure on the dominant thigh was applied during exercise in BFR Group. Two-minute step test, Timed Up and Go test (TUG), and lower limb strength were measured at pre-intervention, mid-intervention (third week), and post-intervention. Statistical analyses were performed using repeated measure analysis of variance. The α level was set at 0.05.

There was a time main effect on 2-minute step test (p0.001) and TUG (p0.001). Post-hoc tests showed 2-minute step test significantly improved at mid- (p0.05) and post-intervention (p0.001) compared to pre-intervention. TUG also significantly improved at post-intervention compared to pre-intervention (p0.05) and mid-intervention (p0.05). Time main effects on muscle strength of bilateral hip flexor (p0.05), dorsiflexor (p0.05) and plantarflexor (p0.05), and right knee extensor (p0.05) and flexor (p0.001) were found. Post-hoc tests showed, compared to pre-intervention, bilateral hip flexor, dorsiflexor, and plantarflexor strength, and right knee extensors significantly improved at post-intervention (p0.05), as well as right knee flexor significantly improved at mid-intervention (p0.001). No group difference was found in all the outcome measurements.

Moderate-intensity aerobic exercise is beneficial for pre-frail elderly in improving aerobic capacity and physical performance. Aerobic exercise combined with BFR did not show additional effect. Using BFR in conjunction with exercise might increase heart rate during exercise, which may overestimate exercise intensity. Consequently the elderly might receive lower exercise intensity than it was expected.

Aerobic exercise combined with BFR may be useful in pre-frail elderly to improve physical performance. However, besides heart rate, an alternate method in determining exercise intensity needs to be considered to have appropriate exercise intensity.