Effect of resistance training volume on walking speed performance in postmenopausal women: A randomized controlled trial

Abstract

Low muscle strength and high abdominal fatness play an important role in fast and usual walking speeds decrement in postmenopausal women (PW). Low-volume resistance training (RT) improves muscle strength. However, high-volume RT has shown to improve muscle strength and abdominal fatness in PW. Thus, high-volume RT would elicit greater improvement in fast and usual walking speeds than low-volume RT. ObjectiveTo confirm whether the high-volume RT is better than the low-volume RT, we performed a randomized controlled trial (clinical trial registration: RBR-8SBBVP) study to investigated the effects of two different RT volumes (three sets vs. six sets) on fast and usual walking speed performances (fast: one-mile walk test and usual: four-meter walk), muscle strength (1RM test), and abdominal fatness (WC – waist circumference; WC/W waist circumference-to-weight ratio; WHtR – waist-to-height ratio; ABSI – A body shape index; BRI – body roundness index; CI – conicity index) in PW. MethodsThirty-three PW were randomized (simple randomization) in three groups: control group (CT – no exercise), low-volume RT (LV) and high-volume RT (HV). The RT consisted of eight total body exercises at 70% of one repetition maximum for 16weeks performed three times a week. ResultsThe fast walking speed (6.1% [CI 95% 2.3–9.9]), WC (−4.1% [CI 95% −6.9 to −1.4]), WHtR (−4.2% [CI 95% −7.0 to −1.4]) and BRI (−10.3% [CI 95% −17.3 to −3.4]) improved in the HV when compared to the LV and CT. The WC/W (−3.7% [CI 95% −6.5 to −0.93]), ABSI (−3.8% [CI 95% −6.5 to −1.2]) and CI (−3.9% [CI 95% −6.6 to −1.3]) improved in the HV when compared to the CT. Muscle strength improved similarly in trained groups (LV: 49.1% [CI 95% 42.5–55.6] and HV: 43.7% [CI 95% 33.0–54.5]) when compared with the CT. No differences were observed in usual walking speed. ConclusionOur results suggest that high-volume RT (six sets) at 70% of 1RM is necessary to promote an improved fast walking speed performance and abdominal fatness in PW.