No matter what your age, your body benefits from regular exercise. It is one of the crucial keys that can unlock the doors to good health. Experts say that a regular exercise program helps you look and feel younger and stay independent longer. It also lowers your risk of various health issues from cardiovascular disease and diabetes to Alzheimer's disease and dementia, certain cancers, high blood pressure, and obesity. According to HelpGuide.org, physical activity even has mental health benefits such as boosting mood and improving sleep.

"Just about everyone should have an exercise program," Dr. Gabe Mirkin, M.D., who is board certified in Sports Medicine, tells Newsmax. "When you exercise, you make your heart stronger and are less likely to die from heart failure, which is rampant today. You also help draw sugar away from the cells of the body and naturally lower blood sugar levels."

The good news is that you don't have to join a gym to reap these benefits. Many community centers offer classes or courses in physical fitness that can do wonders for your health at minimal cost. Here are the top choices for seniors:

1. Swimming. Experts at Harvard Medical School call swimming "the perfect workout." The buoyancy of the water supports your body and takes the strain off painful joints so you can move them more fluidly. Mirkin says that swimming is ideal for those suffering from arthritis.
2. Biking. Mirkin, who bikes long distances several times a week in his 80s, says that the rotary motion of the pedals blunts the force on your joints. He adds that group biking is ideal for older people because they can socialize and get support at the same time. The League of American Bicyclists located in Washington, D.C., was founded in 1880 and is still spinning along, offering safe biking tips and helping people find classes and events nearby.
3. Tai chi. This Chinese martial art that combines movement and relaxation is good for both mind and body. It is like a symphony of postures designed for people of all ages and fitness levels. "It's particularly good for older people because balance is an important component of fitness, and balance is something we lose as we get older," says Dr. I-Min Lee, professor of medicine at Harvard Medical School.
4. Strength training. If you don't use it you lose it, and this definitely refers to muscle tone. Dr. Lee says it's important to engage your muscles regularly even with light weights to keep them strong. You'll also maintain your weight more easily, since the more muscle you have the more calories you burn. Research shows that strength training may also preserve brain function. It's helpful to start by hiring a personal trainer to ensure you have the correct form when you lift weights to avoid injuries.
5. Walking. Simple yet powerful, a daily walking program can help you stay trim, keep your blood pressure in check, strengthen bones, and improve cardiovascular health. According to American Senior Communities, adding at least 30 minutes of walking to your daily routine can lower blood sugar and reduce pain.  It's a low-cost option once you've invested in a good pair of shoes and also promotes social engagement if you choose a walking buddy. Many older folks "mall walk" in an indoor venue when the weather is inclement.