Effects of a Single-bout of Moderate-intensity Aerobic Exercise on Mood and Mental Health Biomarkers in Adults with Depressive And/or Anxiety Symptoms

This study investigates whether a single session of aerobic exercise (like running) can improve the participants' mood and whether such benefits can be explained by changes in the blood factors (like hormones) and brain activity. The main questions this study aims to answer are: * Can a single session of aerobic exercise improve mood? * Which changes in the blood and brain could explain the effects of exercise on mood? Researchers will compare the participants' mood states before and after exercise to see whether exercise can improve mood. The participants will: * Answer questionnaires, collect blood, and undergo magnetic resonance imaging (MRI) before exercise. * Perform 30 minutes of running on a treadmill. * Answer the same questionnaires, collect blood, and undergo magnetic resonance imaging (MRI) after exercise. The entire assessment will last for about 2h45min and will be performed on a single day.