'Even if you've never picked up a weight, Stronger is for you' - Arnold Schwarzenegger No matter how you think of yourself - strong or weak, large or small - you are substantially made of muscle. To the last day of your life, your ability to stand and go where you want to go, your agency and effectiveness in the world, will depend on it. But what is muscle? From the battlefields of Homer's Iliad where muscles first enter world literature, to the Victorian-era gymnasiums where women build strength and muscle by lifting heavy weights, to the retirement home in Boston where a young doctor discovers that training at high intensity can produce the same relative gains for frail ninety-year-olds as for thirty-year-olds, Stronger places the science and significance of our muscles in an astonishing new light. Ancient binaries of brain versus brawn created an enduring prejudice against muscle and against the type of exercise that best builds strength. Yet the research proves that weight training can help prevent or treat many chronic diseases and disabilities throughout life, including depression, cancer, and diabetes. All of us, from elite powerlifters to people who have never played sports at all, can learn to lift weights in ways that yield life's ultimate prize: the ability to act in the world.