Your usual abs exercises routinewas working great—until it wasn’t. Abs, like any other muscles, need progressive resistance to become stronger and more ripped. Think about it: you wouldn’t keep benching 135 lbs. to grow your pecs if you’re capable of lifting double that. It’s not going to get you any stronger or your chest muscles any bigger— you need to add more weight.
Same thing with abs. There’s going to come a time when you’ve done so many crunches that your midsection just becomes used to it. You need to put a strain on these muscles if you expect a six-pack to appear. Or, if you already have one, to maintain it and make it look even sharper.
Be forewarned that some of these are so tough, even the most advanced gym rats may not be able to do many (if any)—at least not right off the bat. “Many people could slop out a few reps of these and not really get anything out of it,” says Eric Emig, personal trainer and founder of Evolution Fitness in St. Louis, MO. “Correct form, of course, is the key.” So focus on doing a few reps of these moves correctly instead of busting out the volume to avoid injury.