Pregnancy

Pregnancy is a time of major change as your body adapts to support a growing baby. Your obstetrician (OB) will monitor you and your baby throughout your pregnancy to support your health and your baby’s growth and development. Most exercise is generally safe and encouraged, and elite and recreational athletes are demonstrating that training can continue throughout pregnancy with modifications to duration or intensity as needed.^1-3 It is important to keep in mind red flags (e.g., vaginal bleeding, dizziness, fluid loss, decreased and/or absent fetal movement) that warrant a medical assessment.³

Eating enough to fuel both training and pregnancy is key, especially as energy needs rise in the second and third trimesters. Folic acid is critical before and during early pregnancy, while iron, calcium and vitamin D, already vital for athletes, become even more important. Choline and vitamin B12 also play essential roles in supporting both mother and baby.^4,5

Lora Webster, Olympic Gold Medalist and mom of four, shares her experience and insight

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“I’m Pregnant. Now What?”

Pregnancy is a remarkable period of change and adaptation.

As an athlete, these changes will impact your energy levels, nutritional needs and capacity for training and recovery. Read on to learn what to expect during pregnancy, and how to support your health, pregnancy and athletic performance.

How to Know for Sure (Diagnosis)

A missed period is often the first sign of pregnancy.⁶

For athletes, pregnancy may initially go unnoticed because missed periods can occur for a variety of reasons, including problematic low energy availability.⁷ Pregnancy can be confirmed through beta-human chorionic gonadotropin (beta-hCG) testing of the urine or blood and an ultrasound.^8,9

Next steps: Schedule an obstetrician (OB) visit, start prenatal vitamins that contain folic acid and seek care if bleeding or abdominal pain develops.

Pelvic Floor

During pregnancy, hormonal changes and increasing pressure from the developing fetus place extra demand on the pelvic floor, which includes the muscles supporting the bladder, uterus and rectum.

Pelvic floor dysfunction can occur because the muscles are weak, tight or not working together, leading to symptoms such as leakage, pelvic pressure or discomfort. Pelvic health physical therapists can assess pelvic floor function and address concerns.¹²

Nutrition

Pregnancy doesn’t replace the need for performance nutrition in athletes; it amplifies it.

Energy requirements rise throughout pregnancy, with nutrition now supporting athletic performance and fetal development.

Athletes should prioritize carbohydrates, protein and the micronutrients listed below.

Athletes have elevated nutrient requirements, such as iron and vitamin D. Regular bloodwork and tailored supplementation can help meet these needs. A pregnant mother’s blood volume increases by up to 50%, so staying well hydrated and meeting increased fluid needs is also important. The American College of Obstetrics and Gynecology (ACOG) recommends drinking 8 to 12 cups of water daily (ACOG Nutrition). Monitoring urine color and increasing fluid intake when urine is dark yellow may help with responding to changing hydration needs.^4,13

^{*Increased iron turnover in athletes warrants more frequent screening of iron, so supplementation can be implemented if necessary.
**Athletes often require larger amounts of supplemental vitamin D to maintain appropriate levels.}

REDs and Pregnancy

Only one study to date has looked at Relative Energy Deficiency in Sport (REDs) and pregnancy outcomes.

In a study of 1,025 previously pregnant participants, those who reported a history of REDs had an increased risk of premature labor and delivery and unexplained vaginal bleeding.¹⁸ Extra attention to fueling and more frequent monitoring may be indicated.

Training While Pregnant

Exercising while pregnant is safe for most and will not negatively impact mom or the developing fetus.¹⁹ In fact, exercise provides mothers with physical and mental health benefits, in addition to supporting their continued involvement in sports.^3,20

Exercise in the form of at least 150 minutes of aerobic training and resistance training is recommended.^3,21 Research suggests that a maternal and fetal cardiovascular system without co-morbidities or complications can tolerate high-intensity interval training and heavy weightlifting in an uncomplicated singleton pregnancy.^22-25 Experienced athletes appear to train and compete at levels exceeding the current activity recommendations, as indicated in a recently published case study of an experienced ultramarathoner.²⁶ However, more research at larger scales is needed, and no guidelines have been changed to reflect this research.³

It is generally recommended to avoid sports that have an increased risk of trauma to the abdominal wall through collisions (including combat and contact sports) or falls (e.g., skiing, snowboarding, cycling), as well as scuba diving, because the developing fetus is not protected from any potential issues with decompression.^3,27

Your heart rate rises over the course of pregnancy to increase cardiovascular output.

ACOG suggests a perceived exertion of 13-14 on the Borg Rating of Perceived Exertion (RPE) scale for moderate to high-intensity exercise.²⁸ The Borg RPE has been shown to inconsistently correlate with maternal heart rate; because of this, monitoring perceived exertion in addition to maternal heart rate may better guide training intensity, though more research is recommended.^3,28

Research on running biomechanics shows that trunk (torso) rotation during running is decreased in the second and third trimester of pregnancy when compared to non-pregnant individuals.²⁹ Further research is needed to explore how the decreased range of motion relates to other physiological changes, including balance and muscle strength, and any association with lower back pain, which has been reported as a barrier to training during pregnancy.³⁰

The 2016 International Olympic Committee (IOC) consensus developed a list of conditions for which exercise may be relatively or absolutely contraindicated.²⁷ These may differ from the recommendations put forth by various professional organizations, including ACOG, the Society of Obstetricians and Gynaecologists of Canada (SOGC) and The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), so verification with your OB is recommended.^3,21,31

Red flags requiring medical evaluation:

Vaginal bleeding, fluid leakage, severe pain, decreased fetal movement, dizziness, chest pain or swelling³

When Pregnancy Doesn’t Go as Planned

Complications may include miscarriage, stillbirth, preterm delivery, unplanned cesarean, preeclampsia, gestational diabetes, hyperemesis or vaginal trauma. Prompt recognition and care are essential. There is insufficient research to determine whether these complications are more or less likely to occur in athletes than in the general population.²⁷