Purpose: The study's purpose was to evaluate the effects of walking (W) and walking plus resistance training (WRT) on cardiovascular disease risk factors in inactive middle-aged (49.0 ± 5.5 yr) African-American women (body mass index = 34.7 ± 6.4 kg·m(-2)).
Methods: Body composition, blood pressure, HDL cholesterol, triglycerides, glycosylated hemoglobin (HbA1c), C-reactive protein, and fibrinogen were measured before and after a 12-wk exercise intervention. Subjects were randomly assigned to one of two training groups. The W group (n = 25) was instructed to increase daily pedometer-measured walking to ≥10,000 steps per day, whereas the WRT group (n = 19) was given the same walking prescription plus supervised resistance training 2 d·wk(-1). A two-way repeated-measures ANOVA with an intention-to-treat analysis was performed to examine changes between groups. Significance was accepted at P ≤ 0.05.
Results: Both groups significantly (P < 0.001) increased walking (W = 5453 ± 2119 to 6845 ± 2279 steps per day, WRT = 4823 ± 1758 to 6859 ± 2012 steps per day). WRT significantly (P < 0.001) increased both upper (100 ± 15 to 113 ± 18 kg) and lower (102 ± 20 to 116 ± 25 kg) body strength compared with W. WRT significantly decreased waist circumference (94.8 ± 12.3 to 92.9 ± 12.0 cm, P = 0.021) and total fat mass (42.6 ± 11.1 to 41.8 ± 10.8 kg, P = 0.036) compared with W. WRT also significantly decreased pre- to postintervention body fat (45.8% ± 6.2% to 45.3% ± 6.2%, P = 0.018), HbA1c (5.9% ± 1.2% to 5.6% ± 1.0%, P = 0.028), and mean glucose calculated from HbA1c (122 ± 39 to 114 ± 32 mg·dL(-1), P = 0.028), whereas W showed no changes. Blood pressure, HDL cholesterol, triglycerides, and C-reactive protein were not affected by either intervention.
Conclusions: Although both interventions increased steps per day, WRT was more effective in improving several body composition measures and glucose control in 12 wk. WRT may be an important addition to a lifestyle intervention aiming to facilitate reductions in cardiovascular disease risk factors in overweight and obese African-American women.