If your goals are: Joint health, st

If your goals are: Joint health, stamina, leg strength, increased immunityBenefits: Because the bike itself bears your weight, cycling is easy on joints, which is good if you have a sore back, or sore knees or hips. It also strengthens thigh muscles and glutes; enhances endurance; and, in studies of older cyclists, keeps muscles and immune systems youthful for years. Ride to and from work, and you combine exercise and transport.Downsides: It’s not weight-bearing, so it doesn’t build bones. You’ll often share roads with cars and fumes, braving pollution and collisions. And riding requires some expertise and, of course, a bike.Good to know: E-bikes—equipped with a small, battery-powered motor—can help you up hills and make long rides fly. But since you still have to pedal, you get a workout comparable to a brisk walk.