Myth 5) Certain forms of exercise build long, lean muscles.
Many forms of exercise claim to lengthen the muscles or develop “lean” muscles, not bulky ones. But here’s a truth that may be shocking to some: To put it another way, no form of exercise makes muscles “longer” because your muscles do not—and will not—respond to exercise by getting longer. It’s just not how they work. Muscles are a certain length because they attach to your bones. A wide variety of movements and exercises can help you strengthen your muscles without necessarily making them bigger. In fact, you can develop a lot of muscular strength without your muscles ever increasing in size (girth).
That said, exercises such as yoga, Pilates, dance and barre classes can help to increase your flexibility (improving your range of motion at certain joints) and your posture, which can give you the illusion of feeling and looking longer or taller. But lengthening? Not possible. Claims like these are just trying to appeal to people who fear bulking up.