Volume and intensity of physical activity in a large population-based cohort of middle-aged and older Australians: Prospective relationships with weight gain, and physical function

Objectives: To examine prospectively whether higher proportions of vigorous physical activity (VPA), independent of total activity volume, are associated with better outcomes in weight maintenance and physical function. Methods: We used three-year longitudinal data (2006/07–2009/10) of adults 45 and older (n = 32,087; 59.5 ± 9.3 years) from New South Wales, Australia. Logistic regression models examined odds of weight gain and functional decline by volume and intensity of physical activity. Results: On average, body weight increased by 0.66 kg (SD = 5.83, p < 0.001); a validated physical function score (MOS-PF) decreased by 4.79 (SD = 12.56, p < 0.001). There was a 10% reduction in the odds of weight gain for participants who reported 300 min/week or more of moderate to vigorous physical activity (MVPA) compared to less than 150 min of MVPA. The proportion of MVPA that was vigorous was not associated with weight change. With the physical functioning outcome, there were independent protective effects from volume and intensity of physical activity. Independent of total MVPA, each 1% increase in the proportion of total activity that was vigorous was associated with a 0.3% decrease in the odds of decline in physical function. Conclusion: These prospective findings indicate that VPA per se plays an important role in the prevention of functional decline.