The goal of this clinical trial is to compare the effects of acute aerobic exercise at two different intensities on psychological measures, symptomology, and time to symptom free in collegiate student athletes with concussion. The main questions it aims to answer are: * Does prescribed, acute aerobic exercise influence measures of pain related fear, anxiety, depression, symptoms, and recovery time? * Does the intensity of the exercise prescription also influence the aforementioned outcomes? Participants will be randomly assigned into either a light intensity or moderate intensity aerobic exercise (treadmill walking) group. They will initiate the exercise protocol 48 hours following their concussion diagnosis, and complete exercise sessions 5 times per week until they report symptom-free. Researchers will compare the light intensity group to the moderate intensity group to see if intensity of exercise influences psychological measures of pain related fear, anxiety, depression, symptomology, and time to symptom-free.