It is necessary to know how to modify certain exercises if you are recovering from an injury, have bad knees or back, or a chronic condition. The following are just a few examples of exercise modifications:
Reduce the pressure you put on your knees by stepping out one leg at a time while doing jumping jacks
Replace a high knee hop with a march
Reduce the pressure placed on the knees, by replacing squats with half squats or wall squats and replacing jump squats with floor taps
Modify squat jumps with squat to heel raise
Reduce pressure on the shoulders and arms by doing a push-up on the knees or wall push-up
While performing a plank, go to the knees or elevate the upper body by placing your arms on a chair or counter.
Almost every exercise can be modified. To increase the intensity or resistance you can add weights or use a resistance band. Make sure to always learn the proper technique before adding the weights. If you are able to perform an exercise in perfect form with no pain, you can then increase the difficulty of the workout by using weights. For example, you can intensify a squat or lunge by holding hand weights or consider adding ankle weights to leg raises. My classes teach you how to regress and progress each exercise so that you can participate in an exercise program given most chronic conditions or right after rehab.