During decision-making, an individual must weigh the value of the outcomes involved while also considering the amount of time until the outcomes will occur. Discounting occurs when a smaller, immediately available reward is chosen over a larger, more delayed reward. Discounting rates are likely related to working memory capacity, because working memory stores and processes the value of the outcomes. The purpose of this study was to examine the relationship between working memory, temporal discounting, and the decision to engage in physical activity. The results showed that working memory capacity was related to the physical activity rates. Discounting rates from a money task and a health task were not related to activity rates. However, in the subsample of individuals who reported that their primary motive to exercise was health, working memory and discounting rates from the money task were both statistically significant predictors of physical activity.