Progressive strength training in sedentary, older African American women

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.

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.

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.

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.