This study compared energy expenditure (EE), economy of movement, and pedometer counts between normal weight and overweight or obese women during a treadmill walking and jogging activity. Participants were 13 normal weight (BMI 22.2 +/- 2.0 kg m(-2)) and 13 overweight or obese (BMI 27.2 +/- 2.1 kg m(-2)) women and all were non-smokers, not regularly active, and able to run 1.609 km continuously at 2.23 m s(-1). Each participant reported to the laboratory on three separate days within a 1-week period. During the first visit, tests for resting metabolic rate via indirect calorimetry, anthropometric measures, and VO(2)max were completed. On the subsequent two visits, participants were randomized to perform either a 1.609-km walk at 1.34 m s(-1) or a 1.609-km jog at 2.23 m s(-1). During each physical activity trial, all participants wore a pedometer to assess steps taken. EE during the 1.609-km walk was 280 +/- 29 kJ for the normal weight and 356 +/- 42 kJ for the overweight/obese women and during the 1.609-km jog was 393 +/- 46 kJ for the normal weight and 490 +/- 59 kJ for the overweight/obese women. In both trials, EE was statistically greater in the overweight/obese women. Economy of movement was not statistically different between the normal weight and overweight/obese women during the walk or jog. In both groups, pedometer counts were lower during the jog than the walk (P < 0.05). These data indicate significant differences in EE between normal weight and overweight/obese women during both a walking and jogging activity.