Oh but not crunches. Full head to knees all the way around from one backside to the other. 5 positions 20 reps per set. After a week of that you can do 500 crunches and not even notice ! Hahaha!
I do abs every day; sometimes with weight added and sometimes just crunches (350 crunches) . I've been doing it that way for 20 years; 365 days/year, so I don't know what difference there might be if I didn't do abs. And I don't want to find out . At age 46 with a sharp 6-pack (or 8-pack if I do extra weighted ab work for a month), it must be working for me…