The latest results of influences of physical training during pregnancy on the foetus are presented. In humane, no pathological effects on the embryogenesis have been demonstrated. During exercise, a modest increase (5-25 bpm) in foetal heart rate is a common finding. This might be caused by reduced oxygen supply to the foetus, but could more likely be due to stimuli from vasoactive hormones or training-induced uterine contractions. Foetal growth seems to be influenced by maternal training, as moderate training has resulted in significantly bigger babies compared to both inactivity and hard training. In one study it was shown that low body weight in babies from hard-training mothers was due to reduced neonatal fat mass. Pathological sequelae due to increased maternal temperature during training have not been found in humans. The results strongly suggest that moderate training during pregnancy can be recommended if simple precautions are taken.