Thigh Muscle Size And Vascular Function After Blood-flow Restricted Elastic Band Training In Postmenopausal Women

Abstract

Several studies have reported that sarcopenia is muscle specific and greater quadriceps muscle loss was found in older adults. Recently, we reported that elastic band training combined with blood flow restriction (BFR) could improve muscle size and strength for upper limb, but did not negatively affect vascular function in older adults. However, the effect of elastic band BFR training on thigh muscle size and vascular function remains poorly understood. PURPOSE: We examined the effect of elastic band training with BFR on thigh muscle size and vascular function in postmenopausal women. METHODS: Postmenopausal women (ages 61-86 years) were randomly divided into a low-intensity elastic band BFR training (BFR-Tr, n=10), a middle-to-high-intensity elastic band training (MH-Tr, n=10), or no training (Ctrl, n=10) groups. BFR-Tr and MH-Tr groups performed squat and knee extension exercises using black or gold bands (Thera-band), 2 days/week for 12 weeks. During BFR-Tr exercise session, subjects wore pressure cuffs (5-cm width) around the most proximal region of both thighs that were inflated to 120-270 mmHg. Observations before (pre) and 3-5 days after (post) the final training session were: MRI-measured muscle cross-sectional area (CSA) at mid-thigh, maximum voluntary isometric contraction (MVC) of knee extension, cardio-ankle vascular index testing (CAVI), ankle-brachial pressure index (ABI), central and peripheral blood pressure (BP). RESULTS: Quadriceps muscle CSA (7.2%) was increased (p<0.05) in the BFR-Tr group, but not in the MH-Tr and the Ctrl groups. Knee extension MVC (14.2% and 11.9%) were increased (p<0.05) in the BFR-Tr and the MH-Tr groups, but not in the Ctrl group. In CAVI, ABI, and BPs, there were no changes between pre- and post- results among the three groups. CONCLUSIONS: Elastic band BFR training improves muscle CSA as well as maximal muscle strength, but does not negatively affect vascular function in postmenopausal women.