7 Day Push-up Challenge

I love this challenge and I need the motivation I'm starting today day 1/100 pushups!

 

Alright - I did 100 pushups in a day once and it was fucking hell, because I was not following the correct form and hurt myself (my arms/shoulders/chest is probably the weakest part of my body, which is weird cause my legs and abs are pretty good), but I would like to get into this challenge, what if I did 100 modified pushups and gradually got to 100 "real" pushups? Also I usually separate between body parts (leg day, arm day, chest/abs day), can It be 100 pushups every first day and 100 sit ups/squats the others (although I usually do planks/russian twists for chest, sit ups are a lame exercise, and also I actually already do AT least 500 squats per day actually)

 

Day 7 of 100 push-ups a day. Did 100 this morning. I try to do them in the morning or in afternoon. I'm feeling pretty great. Got sore day 1 but feel great now. Keep it going bro!!!