Bad Joints?

Got a bad back, bum knee, or trick hip? These kinds of injuries can prevent you from doing typical cardio exercises like biking and jogging. Sometimes even walking is painful. But an old injury isn't a free pass to skip your cardio routine! There are plenty of other lower-impact cardio exercises to choose from.
 

It might be time to hop in the pool — swimming is kinder to your body than land-based exercise because your natural buoyancy in water helps you avoid the jarring knocks that can cause injuries. In water, you weigh about a tenth of your normal weight, and the range of motion for the less-fit person is much wider because the water supports the weight of the limbs.

So, swimming is a good choice for people who want to exercise, but who might have problems with weight-bearing, land-based activities. Swimming might suit those who have arthritis or back problems, extreme weight problems, or are pregnant. To mix things up and target different muscles, vary your strokes during your swim between breaststroke, freestyle, butterfly, and backstroke.