I get back pain after abs training. What should I do?

Keep yourself away from these five mistakes.
1. Hip flexors. Many abs exercises work your hip flexors. But they
shouldn’t be the focus. A basic rule for abs: when performing core
and leg lifts keep the pull on your pelvis and abs and hip flexors
even. When performing sit-ups and crunches, make sure your back
stays flat on the floor to prevent back pain.
2. Back ripper. Careful: abrupt movements can cause one of the
many muscles in your back to seize up. Warm up thoroughly.
Perform the exercises carefully and evenly.
3. Workout wobbler: Always engage your core. The trick:
simply pull your belly button inwards and hold. Just don’t forget
that you still need to breathe!
4. Neck vertebrae no-no. Never tug on your neck with your
hands while doing crunches or sit-ups. That increases the pressure
on the sensitive neck vertebrae. Better: place your fingertips at your
temples. Better still: extend your arms for much more intensity.
5. Bending. If you bend your upper body forward more than 30
degrees from the hips, you need support. If you don’t have
support, you can seriously strain your back. Keep this in mind
when you perform these exercises – many people twist back to grab
weights and the results can be painful.