mended for improving energy expenditure [ 21 ] and as a component of weight management for prevention of weight gain, for weight loss, and for prevention of weight regain after weight loss [ 11 , 49 ] . Increased PA and ET have been included in 88 % of successful weight loss and weight maintenance intervention programs [ 38 ] . A negative energy balance generated by PA/ET will result in weight loss, and the larger the negative energy balance, the greater the weight loss [ 11 ] . A dose eff ect is apparent for PA and weight loss, and higher doses are capable of providing 3 % or greater weight loss from initial weight [ 11 ] . Exercise expenditure > 10 500 kJ/week were substantially better at promoting long-term weight loss than that of < 4 200 kJ activity/week and 4 200-10 500 kJ. Specifi cally, 2.5 years after baseline, participants reporting > 10 500 kJ activity/week lost an average of 7 kg from baseline weight, whereas the other 2 groups had average weight losses of < 1 kg [ 50 ] . Resting metabolic rate (RMR) accounts for 60-70 % of daily energy expenditure and any interventional behavior that chronically alters RMR may have important implications for energy-balanced weight control [ 47 ] . Exercise is
Introduction
▼The higher prevalence of obesity [ 12 ] may refl ect the imbalance between energy intake and expenditure, where energy intake exceeds energy expenditure over some period of time. Similarly, weight loss can occur only when energy expenditure is elevated above energy intake for a period of time. Finally, when energy intake is matched to energy expenditure, body weight remains constant [ 15 ] . To achieve significant safe weight loss, a minimum energy intake of 5 040 kJ/day for women and 6 300 kJ/day for men, respectively [ 38 ] , has been suggested. There is an inverse linear dose-response relationship between volume of physical activity and allcause mortality, and an energy expenditure of about 4 200 kJ/week is associated with a significant 20-30 % reduction in risk of all-cause mortality [ 13 ] . Approximately 31 % (95 % CI 30.9-31.2) of adults are physically inactive, with proportions ranging from 17.0 % in southeast Asia to about 43 % in the Americas and the eastern Mediterranean [ 16 ] . Increased physical activity (PA) and exercise training (ET) is therefore recom-
▼This work sought to determine the fi tness responses and energy expenditure (EE) following once-weekly hill climbing for 16 weeks on diff erent slopes. A cohort of 98 healthy, sedentary subjects (49 female, 49 male) completed the program at their preferred climbing pace. Body composition, resting metabolic rate (RMR) and VO 2 max were measured. EE was measured on 4 slopes (11.6 °, 19.9 °, 14.9 °, and 28.6 °) at the subjects' preferred speed. In males, weight, body mass index, fat mass signifi cantly decreased (P < 0.05), and RMR showed an increasing trend, but the difference was not signifi cant (P = 0.051). In females, the muscle mass increased signifi cantly, and fat ( %) and fat mass signifi cantly decreased (P < 0.05). Absolu...