Your Body: The Missing Manual

Chapter 3. Muscles

Muscles are your body’s movers and shakers. They let you do everything from climbing a flight of stairs to chewing on a piece of beef jerky. But despite their obvious importance, most people have a rather strange way of treating their muscles. Some of us head to the gym and strain them for hours (mostly the stair-climbing muscles, not the beef jerky–munching ones). The rest of us spend more time worrying about other body parts—like the heart and the brain—and assume that our muscles will quietly adapt themselves to the demands of our day-to-day lives.

This is unfortunate, because the health of your muscles is vitally important to the health of your body. Even if your idea of a marathon is watching 12 back-to-back episodes of Gossip Girl, and the only powerlifting you do is moving groceries from the backseat of your car to the kitchen, you can’t afford to ignore your muscles. Strong, well-maintained muscles improve your blood pressure, your bone mass, and your ability to burn calories. They also reduce your likelihood of injury and the risk factors for countless diseases.

In this chapter, you’ll learn the basics of taking care of your muscles. You’ll see how they attach to bones, how they grow, and why the only way to strengthen them is to tear them up ever so slightly with an often-tedious activity called exercise. You’ll also get the truth about stretching, pick up the proper way to lift weights, and learn why a basic strength-training workout won’t turn you into ...