Inclusion Criteria:  age of pregnant women from 20 to 40 years a normal pregnancy confirmed by a gynecologist duration of pregnancy from the 20th to the 32nd gestational week body mass index (BMI) before pregnancy <25 kg/m2 single pregnancy.  Exclusion Criteria:  bleeding in the second or third trimester premature birth in the current pregnancy, rupture of the amniotic sac, preeclampsia or pregnancy-induced hypertension, intrauterine growth restriction (IUGR) in the current pregnancy, anemia not being regular in the physical exercise program at the pregnant woman's own request.