When you move your muscles (and, by extension, your bones), the action stimulates osteoblasts to create more bone. Because this bone-building action slows down as we age, it's critical for children and young adults to get plenty of exercise to take advantage of this process. However, exercise remains vital to maintaining your bone health even in later years. That's because regular physical activity maintains the muscle tone and strength surrounding your bones, which will help prevent falls and injuries that could lead to breaks and fractures. Weight-bearing exercises — those that require your body to carry its own weight, such as walking, jogging, and low-impact aerobics — are very helpful. Even better, however, are strength training or resistance exercises like lunges, planks, pushups, and exercises that require use of resistance bands, dumbbells, free weights, or weight machines (even water jugs and soup cans make great weights). These types of exercises build healthy lean muscle mass that in turn protects the precious bone tissue underneath.