Lace Up or Lie Down? Running Through Pregnancy Safely

Running in ever-tightening spandex while looking out for the next toilet, just in case? Pregnancy is a great equalizer. Not even Cardi B and Kate Middleton could escape the hormonal changes that may cause mood swings, fatigue, nausea, and aches. These symptoms, along with modern culture, often encourage pregnant women to reduce movement and everyday activity. However, research strongly supports that exercise during pregnancy, including recreational running, is beneficial for both mother and baby. So what is beneficial, while also being safe and enjoyable?

While each person with their medical team is best suited to monitor what is safe and beneficial for the body, reliable information to make these decisions is not always readily available. Between the mid-1980s and mid-1990s, around 600 studies demonstrated that prenatal exercise does not harm fetal outcomes, including birth weight, mode of delivery, preterm delivery, Apgar scores, or acute fetal well-being (1-3). The American College of Obstetricians and Gynecologists removed limitations for intense exercise in 1985 (4,5), and reviews show that bed rest does not improve pregnancy complications. Despite this, 95 percent of obstetricians still recommend activity restrictions for certain pregnant women (6).

Clearer guidelines are needed to help pregnant women maintain safe activity levels while supporting both maternal and fetal health. Running is one way many women, especially in New York, embrace prenatal exercise as part of overall wellness. As a recreational runner myself, I found the guidance on running during pregnancy unclear. By observing my own body during pregnancy, I correlated physiological and biomechanical changes with shifts in running mechanics. By the third trimester, I felt it might be wiser to replace running with the elliptical or restorative yoga.

The scientific literature specific to running during pregnancy is limited. In its absence, I used findings for moderate to strenuous physical activity during pregnancy, along with clinical knowledge of pregnancy-related body changes and running patterns, to develop recommendations below. Recent research provides guidance on higher-level prenatal exercise in appropriately selected populations (7,8).

Exercise Recommendations During Pregnancy

Even if starting a running program is not advised during pregnancy, increasing or continuing an appropriate level of physical activity is highly beneficial. Research supports 150 minutes per week of moderate exercise for inactive women, and moderate to strenuous activity for already active women (9). Moderate intensity is 5-6 on the Rate of Perceived Exertion (RPE) scale or 40-59% of Heart Rate Reserve (HRR). Moderate to strenuous activity is 7-8 RPE or 60-84% HRR.

Benefits of properly prescribed prenatal exercise include improvements in:

• Cardiovascular function

• Gestational diabetes prevention

• Strength and lean muscle mass

• Sleep quality and overall sense of wellbeing

• Reduced low back pain and pelvic girdle discomfort

• Healthy gestational weight gain, reducing risks of cesarean delivery, hypertension, preeclampsia, and gestational diabetes

• Psychological wellbeing, including reduced anxiety and depression and improved self-esteem

• Fetal oxygenation and amniotic fluid levels

• Healthy fetal birth weights and development of healthy body composition by age 5

• Gestational age and reduced pregnancy complications

• Delivery outcomes, including faster labor and decreased cesarean rates in supportive settings

• Neonatal outcomes, including higher Apgar scores, better orientation, self-soothing, and early cognitive skills

Safety Boundaries

Strenuous activity can increase miscarriage risk during implantation (20-23 days after last menstrual cycle). Elevation of core temperature above 103°F, from marathon running or hot environments, can increase fetal neural tube defect risk during days 35-42 of gestation. Exercising 60 minutes in a comfortable environment will keep core temperature below 100°F.

Pregnant runners should not exceed 90 percent of maximal heart rate. Physiological changes can make perceived exertion an unreliable gauge, so heart rate monitoring is recommended. The ACOG lists absolute and relative contraindications for aerobic exercise during pregnancy (4), including significant heart or lung disease, incompetent cervix, multiple gestation at risk of preterm labor, persistent bleeding, placenta previa, preeclampsia, severe anemia, and more.

Warning signs for modification of running include low back or pelvic girdle pain, knee or hip pain, pelvic heaviness, sharp pelvic floor pains, urinary leakage, and frequent ankle sprains. Many of these relate to force transfer challenges through the body during running.

Biomechanics of Running During Pregnancy

Pregnancy involves hormonal changes like increased relaxin and progesterone, shifting the body’s center of gravity forward and altering pelvic alignment. Foot arches, knee adduction, hip internal rotation, and pelvic floor tension all change. Running increases the demand on hip stabilizers, gluteus medius, and gluteus minimus to support forward weight shift and ligamentous laxity. The sacroiliac joint may gap during initial strike to single stance, requiring activation of quadriceps, hamstrings, calf muscles, tibialis anterior, TFL, adductor magnus, iliopsoas, and gluteals.

Running modifications to reduce stress include:

• Decreasing speed and vertical displacement to reduce ground impact

• Midfoot strike landing to improve shock absorption

• Increasing arm swing and thoracic motion to distribute forces and support diaphragm-pelvic floor coordination

• Reducing daily physical exertion that increases abdominal pressure

• Using external support such as SIJ belts or foot orthotics

• Strengthening glutes through functional exercises and closed-chain isometrics

• Enhancing dynamic single-leg pelvic stability through exercises like star taps

• Maintaining hip flexor mobility and diaphragmatic breathing

At Hazel Physical Therapy, we are trained in orthopedic or pelvic floor physical therapy and can provide individualized recommendations, as biomechanical and pelvic floor needs differ between people

Expected Running Changes

Approximately 70 percent of recreational to elite runners continue some running during pregnancy, with only one-third continuing into the third trimester. Running volume and intensity are typically reduced by 50 percent. Many who stop running do so due to symptom monitoring, physician advice, or miscarriage concerns. Most women resume running by two months postpartum without affecting breastfeeding (19).

Pregnancy can affect speed, stability, ankle and foot mechanics, resting heart rate, and respiratory patterns. Mild anemia can increase fatigue and breathing rate during runs. Proper, breathable, non-compressive clothing is recommended, along with hydration strategies to account for urinary frequency and urgency.

Looking for pelvic health physical therapy in Philadelphia?

Running and other prenatal exercise provide remarkable benefits for mother and baby. While the activity may look different, goals for a healthy lifestyle remain the same. Be kind to your body, mind, and spirit, and enjoy the opportunity to experience your body’s incredible capabilities during pregnancy.

If you want more individualized treatment including education, exercise, and manual therapy, we would love to help you continue running safely during your pregnancy. This personalized care can make a meaningful difference.  At Hazel Physical Therapy, we provide pelvic floor physical therapy, prenatal physical therapy, and postpartum care in Philadelphia to help you move with less pain and more confidence. Let's connect to see how pelvic health physical therapy might help you in your recovery.

References

1. Wu WH, Meijer OG, Uegaki K, Mens JM, Van Dieen JH, Wuisman PI, Östgaard HC. Pregnancy-related pelvic girdle pain (PPP), I: Terminology, clinical presentation, and prevalence. European Spine Journal. 2004 Nov;13(7):575-89.

2. Franklin ME, Conner-Kerr T. An analysis of posture and back pain in the first and third trimesters of pregnancy. Journal of Orthopaedic and Sports Physical Therapy. 1998 Sep;28(3):133-8.

3. Marnach ML, Ramin KD, Ramsey PS, Song SW, Stensland JJ, An KN. Characterization of the relationship between joint laxity and maternal hormones in pregnancy. Obstet Gynecol. 2003;101:331-5.

4. Bjorklund K, Bergstrom S, Nordstrom ML, Ulmsten U. Symphyseal distention in relation to serum relaxin levels and pelvic pain in pregnancy. Acta Obstet Gynecol Scand. 2000;79:269-75.

5. Aldabe D, Ribeiro DC, Milosavljevic S, Bussey MD. Pregnancy-related pelvic girdle pain and its relationship with relaxin levels during pregnancy: a systematic review. European Spine Journal. 2012 Sep;21(9):1769-76.

6. Albert HB, Godskesen M, Korsholm L, Westergaard JG. Risk factors in developing pregnancy-related pelvic girdle pain. Acta Obstetricia et Gynecologica Scandinavica. 2006 May;85(5):539-44.

7. Moore K, Dumas GA, Reid JG. Postural changes associated with pregnancy and their relationship with low back pain. Clinical Biomechanics. 1990 Aug;5(3):169-74.

8. Biviá-Roig G, Lisón JF, Sánchez-Zuriaga D. Changes in trunk posture and muscle responses in standing during pregnancy and postpartum. PLoS One. 2018;13(3):e0194853.

9. Shiri R, Coggon D, Falah-Hassani K. Exercise for the prevention of low back and pelvic girdle pain in pregnancy: A meta-analysis of randomized controlled trials. European Journal of Pain. 2018 Jan;22(1):19-27.

10. Liddle SD, Pennick V. Interventions for preventing and treating low back and pelvic pain during pregnancy. Cochrane Database of Systematic Reviews. 2015(9).

11. Bogaert J, Stack M, Partington S, Marceca J, Tremback-Ball A. The effects of stabilization exercise on low back pain and pelvic girdle pain in pregnant women. Annals of PRM. 2018;61:157-158.

12. Vermani E, Mittal R, Weeks A. Pelvic girdle pain and low back pain in pregnancy: a review. Pain Practice. 2010;10(1):60-71.

13. Stuge B. Evidence of stabilizing exercises for low back and pelvic girdle pain. Brazilian Journal of Physical Therapy. 2019 Mar;23(2):181-6.

14. Young G, Jewell D. Interventions for preventing and treating pelvic and back pain in pregnancy. Cochrane Database Syst Rev. 2002;(1):CD001139.

15. Elden H, Ladfors L, Olsen MF, Ostgaard HC, Hagberg H. Effects of acupuncture and stabilizing exercises as adjunct to standard treatment in pregnant women with pelvic girdle pain. BMJ. 2005;330:761.

    
    

This post has been adapted from the original post written by Joanna Hess and published on April 2020 on the Beyond Basics Blog.