It is better to do less exercise, but it is not good if you don't exercise all the time. Generally speaking, expectant mothers who are pregnant 16 weeks, that is, within 4 months, should do more aerobic exercise. Swimming is the first choice. Besides swimming, some rhythmic aerobic exercises, such as brisk walking, jogging, simple rhythmic dancing and climbing stairs, can be done once or twice a day. However, sports such as jumping, twisting or rotating cannot be carried out, and cycling should be avoided. Daily housework, such as cleaning the table, sweeping the floor, washing clothes, buying food and cooking, can be done, but if the reaction is serious and vomiting is frequent, it is necessary to reduce housework appropriately. In addition, there is a kind of fitness ball that is very popular recently. Pregnant women can go to a professional maternal and child health hospital or buy it home to do it themselves. The fitness ball is big, soft and elastic, and can bear more than 300 kilograms. Pregnant women are very comfortable sitting on the fitness ball, just like floating on the water, which can greatly reduce the pressure on lower limbs, and can exercise back and forth, left and right, thus exercising the ligament of pelvic floor muscles, which is helpful for childbirth and the growth of baby's small body.