Rational exercising: a lifetime choice with a link between health and happiness

This paper deals with a widespread type of investment in personal health that is not adequately explained by the economic literature. The analysis of people’s choice of intensity of engagement in health enhancing activities is made within an integrative, stochastic, micro-dynamic optimisation framework in which people’s utility is accumulated along a health-dependent random lifespan with direct and indirect mutual effects among exercise, health, consumption, utility, happiness, productivity and survival. Distinction is made between exercise’s length and exercise’s vigour in analysing the effect of exercising on health and rest. A link between health and utility is introduced: health improves (declines) as utility surpasses (falls below) a threshold due to a greater level of happiness (unhappiness).