Are traditional sit-ups OK during pregnancy? If not, what are my alternatives?

Traditional sit-ups aren't recommended for pregnant women after the first trimester because the back-lying position can cause a woman to feel light-headed and dizzy. I recommend doing reverse crunches on a theraball using a resistance band.

In a sitting position on a ball or chair, put the band under your feet, gripping the ends in both hands and then take up slack in the band length until you feel resistance. Lean back 6 to 12 inches pulling the band as you go until you feel your abdominal muscles tighten. Hold that position for five seconds and slowly ease back up in a sitting position. Repeat 10 to 20 times. Remember to exhale as you lean back and inhale as you come forward.