2. Exercise

After eating a healthy diet, regular exercise is the next most important thing you can do to stay healthy. You should exercise at least one-half hour 6 days per week. More is better. If you are deconditioned, you must start gradually. If you have severely arthritic joints that can’t be corrected, you may have to modify your exercise. There is no evidence that impact exercise causes arthritis.

But lack of exercise causes not only general health problems but also joint and tendon deterioration. Obese, deconditioned people get a fatty replacement of their muscles and degenerative tendon tears that are difficult to repair adequately. If you have an arthritic lower extremity joint, exercises such as biking, elliptical, or swimming may still be possible when running and walking are not. If your joints are repaired, but you are deconditioned, I would recommend starting a daily walking program. Gradually advance to 3 miles/day. Once you can walk 3 miles briskly without trouble it is time to start a real aerobic program.

Types of exercise (you need to do all three):

• Aerobic: At least 15 minutes daily at 80% maximum heart rate. Calculate your maximum heart rate using the formula: 220-age. Use an electronic device to measure your heart rate. After 15 minutes at 80% max, you should be out of breath and have a wet shirt. If not, you haven’t exercised adequately.
• Strength: Sarcopenia is the term used to describe age-related muscle loss. It is caused by a loss of normal testosterone levels (in men and women) and a lack of exercise. Resistance (weightlifting) exercise together with hormone replacement is the best treatment. This builds and strengthens muscles and promotes weight loss by burning calories as well as by breaking down muscle, which requires more calories to rebuild them.
• Impact: It is commonly believed that this damages joints. This is not true. Mechanical objects fail with repetitive wear and impact, and biological structures such as cartilage, bone, and tendons are stimulated to get stronger by moderate exercise. Running and jumping; pounding bone makes bone tendons and probably cartilage respond and get stronger. First walking, but finally also some running sports or jump rope or jumping jacks.

Of course, there is usually value in moderation. There is evidence that regular marathon running increases cardiac risk and extreme physical work may break down joints, tendons and cartilage. But most of us don’t do nearly enough. I have found “Younger Next Year” by Chris Crowley to be an excellent book that describes the rationale and methods for proper exercise.