According to the Medical Center at the University of Rochester, keeping fit is important because it serves as an indication of the physical functioning of a person. The Medical Center lists 10 reasons to keep fit.
The top three reasons include bone density improvement, future independence and increasing metabolism. The National Osteoporosis Foundation encourages weight exercises due to its findings that low bone mass may lead to osteoporosis, a disease that causes brittle bones. The Medical Center also recommends lifetime fitness as studies show that those who consistently work out during their lives avoid disability in their final years. Additionally, an increase in metabolic rate from exercise leads to improved control over weight gain.
Proper exercises advised by the National Institute on Aging focus on endurance (running or walking), strength training (push-ups or pull-ups) and balancing and stretching (pilates or yoga). Similarly, the University of Minnesota Center for Spirituality & Healing finds that regular exercise not only increases one's life by five years, but also improves mental health by reducing risk for anxiety, depression and stress.
With exercise also comes improved sleep. The National Sleep Foundation notes that a 2011 study published in Mental Health and Physical Activity found that those who got at least 150 minutes of exercise a week saw a 65 percent increase in sleep quality.