Effects of the Curves® Fitness Program on Muscular Strength, Muscular Endurance, and Maximal Aerobic Capacity

Abstract

0533 PURPOSE: To examine the effects of the Curves fitness and diet program on muscular strength, muscular endurance, and maximal aerobic capacity. METHODS: 123 sedentary women (38.7 ± 8 yr; 93.2 ± 19 kg; 44.8 ± 4.8% body fat) participated in a 14- wk exercise and diet program. Subjects were randomly assigned to an exercise and no diet group (END); an exercise and high calorie mixed diet (2,600 kcals/d for 2 wks at 55% C, 15% P, 30% F; 8 wks at 40% C, 30% P, 30% F; 4 wks at 55% C, 15% P, 30% F) group (HCD); or, a low calorie high carbohydrate (HCHO), high protein (HP), or very high protein (VHP) diet group. Subjects consumed 1,200 kcal/d for 2-wks and 1,600 kcal/d for 8 wks. Subjects then ingested 2,600 kcal/d and 1,200 kcal/d diet at 3/2, 3/2, 5/2, & 10/2 day intervals in an attempt to maintain weight loss. Diets were standardized with 30% dietary fat with carbohydrate intake ranging from 40–55% on the HCD and HCO diets and protein intake ranging from 50–63% on the HP and VHP diets. Subjects participated in a supervised 30-min resistance training circuit program combined with calisthenic exercises 3-d per week. At 0, 10, and 14 weeks, subjects performed 1RM bench press and leg press, 80% of 1RM maximal repetition tests on the bench press and leg press, and a maximal cardiopulmonary exercise test. Repeated measures ANOVA results are presented as means ± SD from baseline. RESULTS: Training significantly increased bench press 1RM (2.37 ± 3.8 kg, p<0.006; 0.04 ± 0.04 kg/kg, p<0.001) and leg press 1RM (15.5 ± 38 kg, p<0.002; 0.27 ± 0.39 kg/kg, p<0.001) [10–15% gain in strength]. Bench press lifting volume (80% weight × repetitions) was unchanged (9.1 ± 126 kg, p = 0.20; 0.3 ± 1.4 kg/kg, p = 0.60). However, significant interactions (p<0.05) were observed indicating the END group experienced greater gains in bench press lifting volume. Leg press lifting volume significantly increased in all groups (325 ± 1,521 kg, p = 0.03; 4.1 ± 14 kg/kg, p = 0.006) with no significant differences among groups. Relative maximal oxygen uptake was significantly increased in all groups by about 7% (1.6 ± 3.5 ml/kg/min, p<0.002) primarily due to a significant weight loss. Resting heart (−4.2 ± 14.0 bpm, p<0.01), systolic blood pressure (−3.2 ± 13 mmHg, p<0.001), and diastolic blood pressure (−2.1 ± 10 mmHg, p<0.03) decreased. CONCLUSIONS: The Curves fitness program promotes increases in muscular strength, muscular endurance, and maximal aerobic capacity while decreasing resting heart rate and blood pressure. These findings indicate that this program appears to be an effective and appropriate level exercise program for this population.