Despite varying study designs and questionnaires, research conducted in different countries
mostly agrees that women tend to reduce the level, duration, and intensity of exercise during
pregnancy [11,18]. Published in 1996, one of the first studies on the prevalence of exercise
among pregnant women was conducted in the United States and found that 42% of pregnant
women reported practicing some form of exercise during pregnancy [16], with walking (43%),
swimming (12%), and aerobics (12%) the most frequent.