Low-frequency physical activity insufficient for aerobic conditioning is associated with lower body fat than sedentary conditions.

We aimed to show the relationships between reported physical activity, fitness level, and body composition in healthy adult office-working Kuwaiti males (n = 45). Reported level of physical activity (group 0 = no routine exercise, n = 10; group 1 = routine exercise once per wk, n = 19; group 2 = routine exercise two or more times per wk, n = 16) was determined from recall questionnaires. Aerobic fitness levels were assessed from resting exercise heart rates and measurement of maximal oxygen uptake (treadmill exercise, Bruce protocol). Body composition was estimated from measurements of body weight, body height, and seven skin-folds. None of the subjects reported dieting to reduce or maintain their body weight. Despite minimal and not statistically significant differences in resting heart rates, VO2max, VO2max/kg body weight, and VO2max/kg lean body mass, the sedentary group (group 0) had a much higher (12–14 kg) average body weight, higher (12–13 kg) body fat, and thicker skin folds than the more physically active groups 1 and 2. Groups 1 and 2 did not differ significantly from each other with regard to fitness and body composition parameters. Thus, routine physical activities insufficient to result in aerobic conditioning were found to be associated with lower body weight and lower body fat compared to those present in subjects reporting the total absence of any routine physical activity. These data are consistent with the hypothesis that even mild levels of routine physical activity are associated with levels of energy turnover that allow less intense and/or frequent periods of positive energy balance, resulting in maintenance of lower body fat than in totally sedentary people. Frequency of participation in routine physical activities may also reflect the level of non-exercise related physical activities and thus relate to the ability to minimize weight gain.