The rate of sedentary activities determines the reinforcing value of physical activity.

In this study, the authors examined whether the reinforcing efficacy of sedentary behaviors was related to their base rates. Base rates of 3 sedentary and 1 physical activity were determined for 40 sedentary adults. Participants were randomized to groups in which either high-rate, moderate-rate, low-rate, or no sedentary activity was contingent on being physically active. Noncontingent sedentary activities remained freely available. Contingent high- or moderate-rate sedentary activities increased physical activity, whereas no increases in physical activity were observed for contingent low-rate or control conditions. Thus, sedentary behaviors can be used to reinforce physical activity, their reinforcing efficacy depends in part on their base rates, and they are not completely substitutable.