Tip: To keep healthy, keep exercising

Anyone who has ever participated in an exercise regimen knows the phrase "No pain, no gain." For people older than 60, the phrase can be amended to "No retrain, no gain."

A study released last month by the American College of Sports Medicine followed two groups, one with members ages 20-35, the other 60-75. Each group performed three sets of resistance exercises (leg presses, knee extensions and squats) three times a week. When members in the older group stopped or cut back on strength training for even a short period of time, their gains in muscle mass disappeared. By comparison, the younger adults maintained some muscle mass even though they cut back on their exercise regimen.

The good news is that older adults can still add muscle mass if they exercise several times a week. But the study concluded that older adults require constant "maintenance" sessions to keep those gains.