The effects of exercise on BDNF, mood, and sleep quality

Neurogenesis is the growth and regeneration of new or damaged neurons in the brain. This process is partially controlled by BDNF, which increases with exercise in rodents. Exercise improves recovery and decreases risk of developing neurodegenerative diseases. BDNF has only recently become easy to measure in humans, and rodent studies show both immediate and long term gains due to exercise. Exercise increases many different aspects of psychological well-being across a wide range of populations. However, these effects are less commonly studied in healthy, young adult populations. While exercise commonly improves mood, there is a possible mediating effect of sleep quality. This study intended to recreate these common effects in a population rarely represented in similar research while examining relationships between these effects. Participants included nine healthy college students who partook in a four-week running program running at least twice per week for 20 minutes each time. Questionnaires were filled out on the first and last days of the study, and saliva was collected to measure changes in BDNF. Significant improvements were found in sleep quality, negative affect, and general life satisfaction. Slight non-significant change was observed in long-term positive affect, and no change was observed in BDNF or immediate effects on mood. Results suggest that running is an effective way of improving sleep quality and long-term psychological well-being. However, there is no support that BDNF is a contributing factor to the positive effects of exercise on psychological well-being. Suggestions for further research are discussed.