Abstract
The aging process is associated with increased risk for disease which can cause physical and economic burden for older adults. In a national longitudinal sample of 3910 participants aged 24-75 years (55% women), we examined psychosocial and behavioural factors associated with physical health in adulthood. With hierarchical regression analyses controlling for Time 1 values of the dependent variable and demographic characteristics, we found that participants reporting better social relations, a higher sense of control, a smaller waist circumference and greater physical activity at Time 1 reported better self-rated physical health (Adj. R
2
= 0.33, F (11, 3661) = 164.66, p < 0.001) and less physical disability (Adj. R
2
= 0.44, F (13, 3659) = 226.25, p < 0.001) 9 years later than their counterparts reported. Furthermore, significant interactions showed that smaller waist circumference and greater physical activity at Time 1 attenuated age-related increases in physical disability. Beneficial effects of physical fitness are considered within the context of lifespan theories of health, and implications for interventions are discussed.