Physical fitness can strengthen bones, build muscles, trim inches from your waistline, reduce your risk of falls and injury, boost your sex life, and improve your overall physical endurance. It can even add years to your life. But physical fitness has benefits for your mental health as well. Regular exercise can help you manage stress, boost your mood, and improve the quality of your sleep at night. Research even shows that exercise can improve your cognitive abilities and reduce your risk of dementia as you age.