Running is one of the best forms of cardiovascular exercise you can find. It's great at burning calories, lowering your body fat percentage and improving the health of your cardiovascular system. Unfortunately, running can also be hard on your joints and can cause some injuries. Fortunately, there are plenty of other forms of exercise that can replace running.
1. Swimming. Swimming is a great place to start a cardio routine. It doesn't require you to support your own body weight (since the water is keeping you up) which makes it a great option for those who are overweight and prone to injuries that are common in runners. If you aren't a good swimmer, there are plenty of flotation devices you can use to help work your way up to a better workout.
2. Cycling. A bike is good low impact alternative to running. Unlike running, you can use a bike to travel long distances which can even save you gas money. Ride your bike to the gym or the store instead of driving or simply ride to your local park just for fun. If you don't own a bike, you can also use the stationary bikes at the gym or sign up for a spinning class. A spinning class is a relatively quick (and high intensity) way to workout.
3. Walking on an Incline. If you like working out on the treadmill but can't run, try walking on an incline. Most treadmills go up to at least a 12% grade which can be just as challenging as a run. When you set the speed and incline high enough, you will burn 400-600 calories per hour without even running.
4. Rowing. If you like doing your cardio at the gym but hate the treadmill and stationary bike, try using a rowing machine. These machines will get your legs and upper body in on the action giving you more of a full body cardiovascular workout. Another alternative to the treadmill and bike is the stair climber which can also be very challenging.
5. Circuit Training. Circuits use strength training exercises (free weights, body weight exercises, machines, resistance bands) with little or no rest in between sets. This keeps your heart rate up just like running and incorporates all the muscles in your body. Circuit training can save you time at the gym by combining elements of both strength training and cardiovascular exercise. This will keep you from having to incorporate them separately into your workout.
The Bottom Line
Though running is a great form of exercise, there are plenty of alternatives that can provide the same sort of benefits running can. Using your inability to run as an excuse to avoid physical activity will leave you obese and at risk for plenty of nasty diseases.