1. High-intensity treadmill running in pregnant athletes did not cause lasting harm to fetal well-being.
2. Fetal bradycardia cases resolved within 8 minutes post-exercise without lasting effects.
3. Fetal tachycardia prompted exercise termination but was transient and resolved without medical intervention.
4. The study involved 60 healthy pregnant athletes between 26- and 35-weeks’ gestation.
5. Exercise intensity targeted a rating of 17 on the Borg Rating of Perceived Exertion (RPE) scale and 90% of estimated maximal maternal heart rate (MHRmax).

Source: BMJ Open Sport & Exercise Medicine