The positive life-prolonging effect of physical activity is often used as a promotion argument to motivate people to change their behaviour. Yet the decision of investing in health by exercising depends not only on the potential health effect but also on the costs of physical activity including time costs and the individual's (dis)utility of performing physical activity. The objective of this study was to investigate the trade-off between costs and benefits of engaging in physical activity. A web-based stated preference experiment was conducted to elicit individual preferences for physical activity among a representative sample of the Danish population, 18–60 years of age, categorised as moderately physically active or physically inactive. The results of the study suggest that perceived negative quality of life impact of physical activity is an important predictor of the choice of not attending physical activity, and hence should be acknowledged as a barrier to engaging in physical activity. Furthermore, we find time costs to have a significant impact on stated uptake. For individuals categorised as moderately active, the marginal health effect of physical activity is significant but minor. For inactive individuals, this effect is insignificant suggesting that information on long-term health effects does not work as motivation for engaging in exercise for this group. Instead, focus should be on reducing the perceived disutility of physical activity.