How Pregnant Athletes Train … Safely

Kickboxer at eight months!

In 1994, very little information was still known about the female athlete and pregnancy. The Eastern bloc countries (and now China) were very interested in the edge that pregnancy hormones offered the athlete and few doctors understood the value of the inner core temperature. A 1950 study by W. A. Pfeiffer revealed that for new mothers who were Olympic athletes and/or record holders, the majority had given birth quickly and easily, and upon their return to athletic competition, they were strong athletes. Pfeiffer believed that the hormones activated by pregnancy improved performances.1

Eastern European nations have known for decades that pregnancy could improve performance, reaching a peak between 8 and 12 weeks, but little data is shared from these nations on what happened to the fetus after this period. I needed more data than that. I was training for the U.S. women’s bobsled team, pregnant with my second child, and squatting over 300-pounds, performing intense plyometrics, and pushing a 400-pound sled. Renowned researcher Dr. James Clapp III, a professor of reproductive biology at Case Western Reserve University invited me into his study on “Active Moms,” as he had never studied an athlete who was doing what I was doing.

Author Alexandra Allred in research lab in 1994.

While training with Dr. Clapp and his staff, I was hooked up to a heart and fetal monitor, EKG leads to measure heart rate and watch PVCs, an EKG change. I also wore an oxygen mask and a rectal thermometer while lifting, running, sprinting and performing plyometrics. The recommendation by the ACOG, based on the average American woman, is that pregnant women should  keep their heart rate at 140 beats per minute. But what of the elite athlete? Clapp’s study revealed that the inner core temperature, which should not exceed 101 degree F, is a far better gauge to determine the safety of the baby while training than monitoring rate. The fetus is one degree Celsius hotter than the mother and has no mechanism (sweating) for lowering his or her body temperature and for this reason, fully understanding how to use a rectal thermometer is crucial.2 (How to use).

With this knowledge, I reached peak performance at the U.S. Nationals and won. Named Athlete of the Year by the United States Olympic Committee, our exercise study was also used by the International Olympic Committee as safety guidelines for elite pregnant athletes. Common sense must prevail while training but when in doubt … get out your rectal thermometer.

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1 Klafs, C. and M. Joan Lyon. (1978). The Female Athlete: A Coach’s Guide to Conditioning and Training. The C.V. Mosby Company, St. Louis, MO. P. 40-56.

2 Clapp, J. (1994. Vol 13. N 2). The Athletic Woman, Clinic in Sports Medicine.