I use the Zen Labs 100 Push Ups app. I was stuck on week 5 day 1 for a couple weeks. But I decided to move up to Week 5 Day 2. The last set is 25 push ups. I can not complete 13 push ups. It's difficult for me to complete more than 25 push ups. Should I do a max set until failure every day? Or should I continue to use the app.