you did 50 pushups per day, then 100/day the second week, 150/day the third week, etc. This went on for 12 weeks where you'd be doing 600/day during the final week.

You get one rest day per week. If you take more than that, you are out.

Anyway, I got to week 8 (400/day) and had to drop out because I got sick and needed more than one rest day. But I was amazed at the improvement. If you had asked me early on if I could have done 400/day the answer would have been absolutely not. But the improvement was real and surprising.