The general recommendation: about 150 minutes per week
For pregnant women without contraindications, both the American College of Obstetricians and Gynecologists (ACOG) and the World Health Organization (WHO) recommend at least 150 minutes per week of moderate-intensity aerobic activity. It is the same general target as for healthy adults, adapted to pregnancy.
Moderate intensity, in practice, means raising your heart rate and starting to sweat, while still being able to hold a normal conversation (the so-called "talk test"). You can split those minutes however you prefer: for example, 30 minutes on five days, or smaller blocks throughout the day. Brisk walking, water aerobics, the stationary bike (more stable than a road bike) and light to moderate strength training are among the cited options.
Why moving helps
The evidence of benefit is consistent. Regular physical activity in pregnancy is associated with:
- Less gestational diabetes. Systematic reviews show a relevant reduction in risk among those who exercise, with good certainty of evidence.
- Healthier weight gain over the course of pregnancy, within the recommended ranges.
- Possibly lower risk of preeclampsia and gestational hypertension. Several studies point in that direction, although the size of the effect varies across analyses. Treat it as a probable benefit, not a guarantee.
- Mood and well-being. It usually helps with energy, sleep and lower back pain, and makes postpartum recovery easier.
An honest reminder is due: reducing risk is not eliminating risk. Exercise is a tool in favor of health, inside well-done prenatal care, not a substitute for it.
What changes by trimester
The body changes, and training follows. Some points that usually come up in the conversation with the obstetrician:
- Avoid lying on your back for long periods from the end of the first trimester. The weight of the uterus can compress large blood vessels and reduce blood return, causing dizziness or a drop in blood pressure. This applies mainly in the second and third trimesters. Standing still for long periods also falls under this caveat.
- Extra care with balance. The center of gravity shifts and the joints become looser. Activities with a risk of falling call for more attention as the belly grows.
- Attention to heat and hydration. Avoid training in very hot and humid environments, and be wary of practices that raise body temperature too much, such as certain types of yoga in a heated room.
- Less impact and less risk of trauma as pregnancy advances, adjusting volume and choice of activities with guidance.
What is usually discouraged
Regardless of trimester, some activities usually stay out during pregnancy because of the elevated risk of abdominal trauma, falling or injury to the fetus:
- Contact sports such as soccer, basketball and martial arts with sparring.
- Activities with a high risk of falling, such as skiing, skateboarding, horseback riding and gymnastics.
- Scuba diving, because the fetus cannot handle the formation of gas bubbles during decompression.
- Exercise at high altitude without acclimatization and specific clearance.
These are general guidelines. Your personal list of what you can and cannot do comes from your obstetrician, who knows your history and how the pregnancy is evolving.
Warning signs: time to stop and see a physician
After delivery: a gradual and individual return
The return to exercise postpartum is also individual. The current trend in guidelines moves away from the idea of a "general clearance at 45 days" and supports a progressive return, according to each woman's recovery, the type of delivery and the clearance of whoever is following her. Starting light, with walking and pelvic floor exercises, and advancing bit by bit is usually the path. Increased bleeding, pain or a feeling of heaviness in the pelvic area are signs to slow down and reassess with a physician or a pelvic floor physical therapist.
What about elite athletes who train while pregnant?
You have probably seen cases of professional athletes competing at advanced stages of pregnancy. They are exceptions closely followed by medical teams, with years of training history and constant monitoring. They are not a parameter for the daily life of most pregnant women. What works for an elite athlete under specialized supervision does not automatically transfer to someone starting or resuming. Compare yourself with your own history and with the guidance from your prenatal care, never with the headline.
How Darwin fits in
Darwin does not prescribe training during pregnancy and does not replace the obstetrician. What the platform does is help you record, organize and track the activity that has already been cleared by your health team, and bring clear information to that conversation. The clinical decision is, and remains, with those caring for you and your baby.
