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.

Objective: To 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.

Methods: Thirty-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.

Results: The 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.

Conclusion: Our 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.

Keywords: Abdominal fat; Aging; Gait speed; Weight lifting.