One of the most important tools as a personal trainer or group fitness instructor is to learn how to quickly and effectively modify or regress an exercise to make it easier or progress an exercise to make it harder. When you learn these strategies you are able to more easily fine tune your workout to meet your client needs based on their fitness level or a possible injury. Also, in a group fitness setting you can lead a routine that works for all participants and their fitness level increasing the success and accessibility of your class. It’s typically harder for fitness instructors to make exercises easier versus harder.

Start with level one, demonstrate and cue to get participants started then add layers (options) to "add more challenge" if they want. Go to next level while demonstrating instead of starting harder and saying, "if you can't do that". Also, you may say, "if you have wrist issues, try doing this on your forearms". Give those options while instructing and it will be very enlightening to see how many take them! See below common methods to reduce and add challenge to exercises.

Less Challenging

Shorten lever length (bend knee or elbow)
Alternate one arm/leg at a time
Modify the range of motion. For example, don’t go down as far on a squat, lunge, or push-up. Or modify how high your legs or arms go.
Bring your elbows or knees down.
Reduce amount of weight used or resistance.
Tapping the feet, stepping, or walking/marching versus jumping
Moving versus stationary. For example, lunges in place keeping same leg versus walking lunges or alternating legs.
Use the wall for balance
Modify the incline or decline angle.

More Challenging

Add instability – balance on one leg, mini ball, stability ball or BOSU
Increase amount of weight or resistance.
Add plyometrics when appropriate (make it explosive)
Modify the incline or decline angle.
Turn a double leg (DL) or double arm (DA) exercise into a SL or SA exercise (unilateral)
Add “mini reps” in the middle or at the end (pulse)
Change resistance type
Change your grip
Change the tempo – ie, up 2, hold 2, down 4 or slower or faster reps
Add a pause between eccentric and concentric contractions
Add a combination – ie, squat with DB press, lunge with bicep curl
Increase ROM
Decrease points of stability

Common Issues

Low back
Wrist issues
Shoulder issues
Knee pain
Can't jump (explosive)
Trouble balancing
Spinal alignment/posture