The way an individual uses one's time can greatly affect his or her health. The purpose of this article was to examine the cross-sectional cross-elasticity relationships for use of time domains in a sample of Australian adolescents. This study analyzed 24-hour recall time use data collected using the Multimedia Activity Recall for Children and Adults (N = 2,200). Using simple linear regression, the authors calculated the difference in time devoted to a reference activity (i.e., screen time, sleep, or social) given 1 hour extra in the time devoted to a criterion activity (i.e., physical activity). The most elastic activities were screen time and school-related time. Every additional hour committed to physical activity was associated with 32 minutes less screen time. This relationship was more pronounced in obese adolescents (-56 minutes screen time) compared with normal (-31 minutes) and overweight (-27 minutes) adolescents. Promising behavior patterns exist, with screen time appearing as a highly elastic behavior. (Contains 2 tables.)