Strength training, also known as resistance training, is not only for body builders and the physique-conscious.

From age 50 to 70 you can lose 20 to 40 percent of muscle and 30 percent of your strength. Age-related loss of muscle mass and strength, known as sarcopenia, contributes to decreased physical function – including problems with balance – that can lead to falls.

People with rheumatoid arthritis (RA) may be at even greater risk of muscle loss. More than half of those with RA are affected by cachexia, a condition in which muscle mass decreases while fat mass increases, leading to fatigue, infection and even disability.

The good news: You can reduce the risks of sarcopenia and cachexia without pumping iron at the gym. Resistance training can be done with light dumbbells, rubber exercise tubing or water bottles.

Here are three more reasons to include resistance training as part of your wellness program:

Less arthritis pain. High–intensity resistance training, defined as 70 percent to 75 percent of maximum effort (the most weight you can lift during one rep), decreased pain by 53 percent in a study published in the Journal of Clinical Rheumatology. "Everyone felt better at the end of the training sessions, even if they were in pain before they started," says lead author Hilary Flint-Wagner, associate professor of kinesiology at Boise State University.

Better mobility and daily function. Resistance exercise two to three times a week helps you perform daily tasks such as walking, climbing steps or getting out of a chair more easily. In one study review published in Arthritis & Rheumatism, 50 to 75 percent of participants reported improved functioning. "In some cases, people who used a cane to walk no longer needed it," says Flint-Wagner.

Lower risk of heart disease and stroke. "Both cardiovascular exercise and resistance training increase blood flow, which creates a cardiovascular benefit," says Johnny Lee, MD, cardiologist and president of New York Heart Associates in New York City. This benefit is especially important for those with rheumatoid arthritis who have a higher risk of heart decrease.

Have your doctor or physical therapist screen you and suggest a strength training routine appropriate for your needs.