To ensure safety, buy good running shoes, warm up, run on forgiving, smooth surfaces like a track or asphalt, and stop if you feel pain. Bicycling does not involve the pounding of running, but accidents can happen. It, too, provides an excellent aerobic workout, and the risk of serious injury can be reduced greatly if you wear a helmet. Adjust the seat so your knees are slightly bent when the pedals are closest to the ground. Water exercises are the gentlest aerobic activities because the water buoys your body and cushions the joints.
Swimming also works muscles throughout the body.
It provides a superb workout for people who have arthritis or other muscle or bone problems. Swimming, though, is not as accessible as land exercises. In addition, you need to work harder than you would on land to raise your heart rate to the same level. This activity works all the major muscle groups, and you may find the variety of moves fun. Proper footwear and lower-impact aerobics decrease the risk of injury.