For pregnant women who've had back pain before, doing gentle strength exercises twice a week for 12 weeks might make their legs and lower back stronger and more enduring, without hurting them or raising their blood pressure.

Pregnant women who've had back pain before can safely do supervised strength training for 12 weeks and get stronger—especially in their legs and lower back—without feeling like they're working any harder than before.

For pregnant women with back pain who are otherwise healthy, doing light to moderate strength training twice a week for 12 weeks seems safe — most women don’t get hurt, and only a tiny number feel a little dizzy or have mild belly or pelvic discomfort.

When pregnant women do supervised strength training, they can do more lower back exercises without getting as tired, which means their back muscles are working more efficiently.

When pregnant women do supervised strength training, they're likely to feel less back and sciatic pain—by about half—and find it easier to move around and do daily tasks compared to those who just get regular prenatal care.

When pregnant women do supervised strength training, they tend to gain less weight than usual, feel less back and sciatic pain, and feel stronger, more energetic, sleep better, and feel more mentally well.