Impact

Impact in exercise refers to the physical forces that are experienced by the body.  We generally classify exercises as either low impact or high impact.  Low impact exercises place less stress on the weight bearing joints than high impact exercises.  Good examples of low impact exercises are walking, cycling, swimming, water aerobics, gardening, and, when done right, jump rope (low jump on a rebounding or cushioned surface).  High impact exercise, on the other hand, includes activities with a lot of running and jumping, like running, tennis, basketball, etc.  To give you an idea about the difference between high and low impact exercise, running puts about 3-4 times your body weight on your knees with every stride, compared to 1.5 times your body weight with every walking step.

Remember: before starting an exercise program, talk with your doctor first.