Back Pain And Ab Crunches

Why am I getting back pains while doing crunches?

Your lower back is just like your abs so if you have a weak lower back then it will cause you aches when doing crunches.

Do back extensions and bridge exercise to strengthen your lower back, Do three sets of 15 to 20 reps for back extension and 5 sets of 10 seconds holds and you will be having a better lower back in one month time provided you hit your daily macros.

You can add weight to back extension exercise (you can hold plates with your hands) when you become a pro and you can extend your bridge pose time to 20 seconds or more when you master that exercise too.