Physical activity and aerobic exercise are increasingly recognized as lifestyle choices that benefit the brain and thought processes. This study assessed performance changes on two different mental tasks immediately after exercise. Unlike other studies that compare aerobic exercise to seated rest, the researchers compared each person’s moderate-intensity cycling to passive cycling where their legs were moved by motorized pedals without significantly raising heart rate. The study found that 30 minutes of moderate-intensity cycling improved the subject’s ability to mentally store and update multiple features of information continuously (i.e., working memory). Working memory improved about 6.4 percent without significant changes in the subject’s ability to control irrelevant information (i.e., inhibitory control). Passive cycling affected neither ability. The selective effect of aerobic exercise on working memory suggests that specific brain systems are affected more than others.