Muscle and bone: Use it or lose it

Starting at around age 30, muscle strength and bone mineral density naturally begin to diminish. Untempered, these changes increase your risk of falls, fractures and conditions like osteoporosis. Regular exercise has been shown to slow or stop muscle and bone loss. And the right kind of exercise can even trigger the body to build new muscle and bone.

Different physical activities benefit your muscles and bones in different ways:

Aerobic activities work large muscle groups, increase your heart rate and help your body in countless ways. But for an aerobic activity to benefit your bones, it needs to be weight bearing. This means you are on your feet, moving your body against gravity. Dancing and walking are weight-bearing activities, but cycling and swimming are not. The higher the impact (think jogging and jumping rope), the bigger the benefit for your bones.

Muscle-strengthening activities include lifting weights, using resistance bands and doing body-weight exercises like pushups, lunges and squats. These activities use resistance to make your muscles work harder than they usually do — which makes them stronger. Bonus: Muscle-strengthening exercises offer some bone-building benefits, too.