I can't tell you how many times people say this to me about yoga. They can't figure out why on earth anyone would want to practice yoga... it's just stretching, right?
Well... wrong. Very wrong. But... what if they were right? What if yoga WAS "only" stretching? Would that be a totally bad thing? Would that be unvaluable?
I don't think so. Our bodies are made up of approximately 600 skeletal muscles. Muscle tissue easily stretches, and it can be safely stretched up to 50% of its resting length! Stretching these muscles helps to maintain the health of our joints, muscles and connective tissue. It also helps to maintain the resilience of muscles, which allows pain-free movement.
Underuse of muscle tissue causes atrophy and weakness. Overuse causes strains and tears. Gentle stretching keeps the muscles in an optimal state. Excessive tension in muscles causes tight spots and chronic aches and pains; stretching can ease this tension. Aging in the body can cause a loss of range of motion; stretching can help to prevent some of this loss. If you're a "weekend warrior" and did a little too much gardening last weekend, stretching can help to relieve muscle soreness.
Stretching helps to preserve and maintain the joints of the body by bathing them in synovial fluid, which is a lot like "oiling" stiff joints. Stretching before a more vigorous activity can help prevent injuries; stretching afterwards can help to realign muscle tissues and prevent soreness. Why wouldn't you want to stretch?
Of course, yoga is so much more. Physically, yoga increases flexibility and also increases strength. Connecting your yoga practice with your breath increases lung capacity and is beneficial to your entire respiratory system, heart and circulatory system. Yoga helps to increase your energy, stamina and endurance. It improves your balance. It improves your overall quality of life.
Call it stretching if it makes you happy; I'll keep calling it yoga because I know it is so much more than simple stretching. Whatever you decide to call it, don't underestimate the power of a good yoga class!