That isn't just true for women who were super fit before pregnancy, say researchers in May's issue of Medicine & Science in Sports & Exercise. The finding was seen in women with lean, average, and heavier prepregnancy bodies.
"Our major findings include decreases in both maximal oxygen consumption (a measure of fitness) and leg strength from pre-pregnancy to six weeks post-partum, with some of these observed decreases recovering by 27 weeks post-partum," write Margarita Treuth, PhD, and colleagues.
Fitness Before Pregnancy
Treuth's study included 17 women with low body mass index (BMI), 34 with normal BMI, and 12 with high BMI before pregnancy. The women were around 30 years old, on average.
They took fitness and strength tests before pregnancy and again at six and 27 weeks after giving birth. The women rode stationary bikes and hit the weight machines, lifting as much weight as possible with their legs and arms.
The group had a wide range of fitness levels before pregnancy, say the researchers.