Exercise During Pregnancy: What the Research Really Says

Pregnancy comes with a lot of advice and often, a lot of fear. Many people still hear outdated warnings like “keep your heart rate under 140,” “don’t lift weights over 20lbs,” or “rest as much as possible.”

But modern research is clear: Exercise is safe, healthy, and recommended for most pregnancies. So let’s end the discussion of whether exercise is safe or not because we know that it is. Instead let’s talk about how it helps.

Here’s what the evidence actually shows — and what that means for you.

Exercise Does Not Increase Risk

Large systematic reviews and international guidelines all point to the same conclusion:

✔ Exercise does NOT increase the risk of:

• Miscarriage

• Preterm birth

• Placental complications

• Low birth weight

• Fetal distress

• Birth defects

Studies following thousands of pregnant people found no difference in miscarriage or preterm birth rates between those who exercised and those who didn’t. Even moderate-to-vigorous activity showed no harmful effects on fetal growth or wellbeing.

One major guideline update emphasized that physical activity should be encouraged, even for individuals previously inactive — as long as there are no contraindications.

The Benefits Are Huge

• Lower risk of gestational diabetes

• Reduced excessive weight gain

• Less back, hip, and pelvic pain

• Improved cardiovascular fitness

• Better mood and lower anxiety

• Higher chance of a vaginal delivery

• Lower rates of instrumental delivery

• Improved postpartum recovery

• Reduce fear of birth and improve overall wellbeing

What “Helpful Exercise” Actually Means

Moderate intensity is the sweet spot

You should be able to talk but not sing. Your breathing increases, but you remain in control. For people who were already active, it’s safe to maintain higher intensities with appropriate monitoring and self-awareness.

Strength training is not only helpful, it’s recommended

Research shows strength training:

• Maintains muscle needed for pregnancy and postpartum

• Reduces pain

• Improves functional capacity

• Supports an easier postpartum rebuild

What matters is good form and controlled load

Aerobic exercise is highly supported

Walking, cycling, swimming, rowing, hiking, stair climbing, and low-impact cardio all improve maternal and fetal outcomes.

Pelvic floor and core training matters

Coordinating breath, pressure, and pelvic floor engagement helps with:

• Pelvic girdle comfort

• Body mechanics

• Labor preparation

• Postpartum return to activity

Know the red flags

Stop and seek guidance if you have:

• Vaginal bleeding

• Dizziness

• Chest pain

• Severe shortness of breath

• Leaking fluid

• Painful contractions

Outside of these symptoms, movement is encouraged.

Myths That Need to Go

Myth 1: “Exercise raises miscarriage risk.”

False. Multiple high-quality studies show no increased risk.

Myth 2: “You should avoid lifting weights.”

False. Resistance training is safe and beneficial with proper technique and modification.

Myth 3: “Heart rate shouldn’t exceed 140.”

Outdated. There is no specific heart rate limit recommended by modern guidelines. Intensity should be based on perceived exertion.

Myth 4: “Exercise can cause preterm labor.”

False. Research shows no link between exercise and early labor in uncomplicated pregnancies.

Myth 5: “If you weren’t active before, you shouldn’t start.”

False. Starting gentle-to-moderate exercise while pregnant is safe and recommended.

Modern research is clear:

Exercise during pregnancy is safe, beneficial, and recommended for the majority of healthy pregnancies.

Instead of asking, “Should I stop training?” a better question is:
“How can I adapt my training so I feel strong, supported, and confident throughout pregnancy?”

Your body is capable. Your movement matters. Staying active is one of the best things you can do for both you and your baby.

Sperstad JB, Tennfjord MK, Hilde G, Ellström-Engh M, Bø K. Diastasis recti abdominis during pregnancy and 12 months after childbirth: prevalence, risk factors and report of lumbopelvic pain. Br J Sports Med. 2016;50(17):1092-1096. doi:10.1136/bjsports-2016-096065

Prevett C, Kimber ML, Forner L, de Vivo M, Davenport MH. Impact of heavy resistance training on pregnancy and postpartum health outcomes. Int Urogynecol J. 2023;34(2):405-411. doi:10.1007/s00192-022-05393-1

Wowdzia JB, Hazell TJ, Berg ERV, Labrecque L, Brassard P, Davenport MH. Maternal and Fetal Cardiovascular Responses to Acute High-Intensity Interval and Moderate-Intensity Continuous Training Exercise During Pregnancy: A Randomized Crossover Trial. Sports Med. 2023;53(9):1819-1833. doi:10.1007/s40279-023-01858-5

Jones PAT, Brockwell E, Dufour S, Hassan A, Matenchuk BA, Davenport MH. What are the Risks of Contact Sport During Pregnancy: a Survey-Based Investigation. Sports Med. 2025;55(12):3143-3156. doi:10.1007/s40279-025-02262-x

Moolyk AN, Wilson MK, Matenchuk BA, et al. Maternal and fetal responses to acute high-intensity resistance exercise during pregnancy. Br J Sports Med. 2025;59(3):159-166. Published 2025 Feb 3. doi:10.1136/bjsports-2024-108804

Youssef A, Montaguti E, Dodaro MG, Kamel R, Rizzo N, Pilu G. Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women. Ultrasound Obstet Gynecol. 2019;53(5):686-692. doi:10.1002/uog.20159