Muscle weakness contributes to numerous problems, including arthritis, back pain, and falls in the elderly. Studies have shown that even people in their 80’s and beyond can make rapid gains in function when they adopt a regimen to build muscle. Asana practice not only strengthens muscles but does so in a functional way, attending to every area of the body, balancing strength with flexibility. In addition, yoga builds endurance and increases energy and fights fatigue. (Source Timothy McCall, M.D.)
Yoga builds physical strength, and also helps create a sense of mental and emotional strength. People who practice yoga regularly can often deal with mental and emotional stress with significant ease.