Progressive strength training in sedentary, older African American women

Abstract

Purpose: This study investigated effects of an 8-wk, low-frequency and low-volume, supervised, progressive strength training program emphasizing free weight, multijoint movements on the muscular power, strength, endurance, and flexibility of African American women 44 to 68 yr of age.

Methods: Nineteen sedentary African American women were randomly assigned to a strength training (ST) only group (N = 12; mean age, 51 yr) or a nonexercise control (C) group (N = 7; mean age, 52 yr). Maximal power, strength, absolute endurance, and flexibility were assessed before and after training. Subjects trained 2 d x wk(-1) using free weight (barbells and dumbbells) and machine (plate loaded) exercises for two to three sets of 8 to 10 repetitions on both primary and assistance exercises.

Results: Upper body power (medicine ball put distance) significantly increased statistically (P = 0.002), but gains possibly lacked practical significance because of measurement variation. Lower body power (peak watts on bicycle) experienced a small, nonsignificant increase in the ST group. Significant increases (P = 0.000) in 1RM muscle strength occurred in the ST group (leg press, +99.8%; bench press, +34.4%). Absolute endurance significantly increased (P = 0.000) in the ST group (leg press repetitions to failure at 70% pretest 1RM, +221%; bench press repetitions to failure at 50% pretest 1RM, +112%). Significant flexibility gains occurred in the ST group (sit-and-reach test, +8.2%; P = 0.017). No significant changes occurred in power, strength, absolute endurance, or flexibility in the C group.

Conclusion: This study demonstrates that 8 wk of low-frequency, supervised, progressive strength training emphasizing free weight, multijoint movements can safely cause significant gains in muscle strength, absolute endurance, and flexibility in older African American women.