Bike, running, swimming, walking, light weights (I was told to not lung or squat when doing weights so I only do them sitting down and use 3, 5, 8 lbs max). Just try to tone down and watch intensity and heart rate. Depending on your age there are different ranges to stay in when pregnant. I am 28 yrs old and have read for my age to aim for 135-155 for my heart rate.