There is something that you must remember, muscle size is not in direct relation with strength. If that were true, bodybuilders would be terribly strong and they aren't. Thus, may it not come as a surprise to you that maybe you are able to perform more dips even though your muscles are smaller. Strength is directly related to the development and condition of tendons and ligaments.
Since you are speaking of chest size, I will concentrate on lesson 1. First, I would recommend to maybe vary the order in which you carry out the exercises. Maybe your body has become used to the routine and you need to vary things up a little bit. What works for me is to do lesson 1 in sort of a circuit, as detailed below. As for reps, for the dips try to get around 75% of your maximum number. For the rest of exercises, try to hit 10-12 reps under heavy tension. I would recommend to rest between 45-60 seconds between exercises and to really concentrate in your muscles while training. Remember to listen to your body, and to "train, don't strain".
[*]1 set of dips
[*]1 set of exercise 2
[*]1 set of dips
[*]1 set of exercise 3
[*]1 set of dips
[*]1 set of exercise 4
[*]1 set of dips
[*]1 set of exercise 5
[*]1 set of exercise 6
[*]1 set of exercise 7
This has worked for me, maybe you can give it a try. It would be nice if you share your numbers and where you are in the course. Good training!!!
