Good question. Wish I had a good answer. I did complete Day 3, and almost made the requird set, but then the wobbly arms afterwards makes it very hard to do my other work, so it sort of just petered out.
I could see I was slowing improving on the total number of push-ups completed each day, although at a slower rate than the program suggests. Maybe I’m just not cut out to be Buff 
One day when I have more time on my hands (yeah, right) I might give it another go.
Russell.