Long-term Exercise Improves Cognition, Mood, And Motivation While Affecting Brain State In Low-fit, Middle-aged Adults

Physical activity is known to improve sleep and mental health outcomes in humans. However, the effects of exercise on hippocampal-dependent functions, such as spatial memory, pattern separation, and novel object recognition, remain understudied in humans. PURPOSE: To examine the effects of long-term exercise on neurobehavioral processes, including psychological state and cognitive function, as well as brain physiology. METHODS: Healthy male and female adults between the ages of 30 and 59 (n = 44) completed the study. All participants were sedentary and low-fit, meaning that they engaged in 2 or fewer aerobic exercise sessions per week in the past 3 months. Participants were randomly assigned to 3 months of a physically active (n = 17) or sedentary (n = 27) experience. Before and after the 3-month period, participants completed self-report questionnaires and neuropsychological assessments. 20-electrode EEG data were recorded during a 10-min open eyes session where participants looked at a cross-hair in the middle of a computer screen. Each group participated in three 45-minute sessions per week during the 3-month period. A session was an indoor cycling class (physically active) or a non-physically active video game (sedentary/control). RESULTS: Exercisers reported a significant improvement in positive affect and body image. Participants in the exercise group maintained exercise motivation (BREQ-2: Relative Autonomy Index [RAI]: time F(1,14) = 3.280, p = 0.092, partial η2 = 0.190), whereas exercise motivation decreased in controls (time F(1,12) = 5.124, p = 0.043, partial η2 = 0.299). Exercise also improved response time for correct responses on the Stoop Trask (Exercisers: time F(1,16) = 15.035, p = 0.001, partial η2 = 0.484; Sedentary: time F(1,10) = 0.033, p = 0.860, partial η2 = 0.003). Relative power in delta, theta, and alpha frequency bands in EEG also increased in the exercise group. There was a significant correlation between theta activity and body image (r = -0.477, p = 0.025). Central alpha activity was also significantly associated with exercise motivation (r = 0.490, p = 0.021). Future EEG explorations will examine changes in intra-brain coherence during resting state measures. CONCLUSION: Long-term exercise benefits brain function and physiology in middle-aged adults who were originally sedentary. National Center for Advancing Translational Science of the National Institutes of Health Award UL1TR003015/KL2TR003016.