Exercise intensity and energy expenditure analysis of women participating in the Curves® exercise program

The Curves fitness program is a popular form of exercise for women that involves interval resistance‐training interspersed with callisthenic exercise. The goal is to maintain an elevated heart rate during resistance‐training to efficiently promote aerobic and anaerobic fitness. While the program has been shown to promote fitness gains, the exercise intensities of women participating in this program are unclear. We conducted two studies to determine the exercise intensities of women participating in this program. In the first study, 40 women (49±9 yrs, 91±14 kg, 45±5 % fat, 69±8 RHR, 159±18 max HR) performed the Curves workout on two occasions. HR was determined using Polar heart rate monitors. Max HR was obtained during a max treadmill GXT. HR observed during the workouts was compared to max HR and heart rate reserve (HRR). Results revealed that mean HR was 126±15 b/min which was equivalent to 80% max HR or 64 % of HRR. In the second study, 12 post‐menopausal women (52±4 yrs, 83±13 kg, 1.76±0.25 L/min VO 2 max, 6.2±1.0 Max METS, 1.27±0.2 L/min VANT, 73±3 % max VANT) performed the Curves 30‐min workout on two occasions. Exercise VO 2 and CO 2 measurements were measured using a CosMed K4b portable metabolic measurement system. Results indicated that the mean VO 2 to perform the 30‐min workout was 1.14±0.29 L/min representing 65±10% of VO 2 max. Estimated energy expenditure was 5.7±1.1 kcal/min or 172±35 kcals with a mean RER of 0.94±0.7 for the 30‐min workout. Exercise VO 2 for session 1 and 2 were not significantly different and were significantly correlated (r=0.84, p<0.001) indicating the exercise sessions were reliable. Results indicate that the Curves program elicits a mean exercise intensity that meets ACSM and AHA recommendations for improving aerobic fitness in this population of low‐fit post‐menopausal women.