For the first time, I wasn't sure if I could actually physically do the work out. I barely made it (and that was with gritted teeth), even with extended rest sessions between reps. And, boy, do I feel it.
However, it might just be wishful thinking, but...my triceps do feel firmer. And I know I've made progress. I think I've done more pushups in the past two weeks than I have in my entire life up until this point.