I am personally coming back to simplefit after trying other programs and missing it. The reason I left in the first place was that the high volume aggravated old knee and shoulder injuries. My response this time is to use only narrow hand placement and slow reps. So, that is chin-ups only, hands slightly less than shoulder wide, no body swings, two seconds up, one second pause, two seconds down, stop when arms are straight but never lower lower shoulder. For push-up, that is hands directly under my arm-pits and elbows at my sides. Again, two seconds down, one second pause, two seconds up. For squats, I sub in a static hold near the point of parallel, weight on my toes instead of heels, hands near the floor, 5 second hold for every required rep. My joints are loving this and I am seeing really good progress. I have finally admitted that it is not worth it to just push through the pain. I would rather take it easy than have to miss out on something fun on a Saturday morning.