Are crunches a waste of time?

Peeeeeeeeeej

Bicycle Crunch - 20 reps (upper abs and upper obliques)
Hanging Leg Raises - 15 reps (lower abs)
Side (oblique) Crunches - 10 reps per side - with the last rep held till failure (obliques - raise those legs and keep them slightly bent to really work out the lower obliques)
Supermans - 15 reps (lower back)

^^^This is the kind of thing that's a waste of time, IMO. Doing the basic barbell lifts, with a few heavy sets a week if you're so inclined, is plenty.

How is this a waste of time - ever since I've added core workouts to my workout regimen, my bench, my squats (if my knee isn't bothering me), my lifts, my pullups - everything that I do has gotten incredibly stronger - the problem is that if you don't have a strong core - you'll never be that strong - and a lot of people who aren't physically fit (i.e. they are an athlete) have weak cores

Fit_Forever25

Not at all .. if you keep your heart rate up by mixing them with some cardio exercises for 1-2 mins then they works magically.
I always mix these low intensity exercises with cardio or modify them with some dumbells or Swiss balls.
I think they work pretty well.

KLK1986

Not totally useless! Once the fat is gone, they help you define your ab muscles a bit more. Believe me, my fiance's abs say it all, lol!

atomiclauren

I'll echo what others have mentioned and add something Jackie Warner has mentioned, and it has to do directly with what your goal is:

Crunches are not going to change your body shape at all. Diet is the key. If you don't change your diet, then doing crunches will add only muscle to your shape and can actually make you appear larger. The best exercises for changing your body shape and strengthening the core is to do push-ups and weighted squats.