Intense Exercise During the First Two Trimesters of Unapparent Pregnancy

G C Cohen; Jerilynn C Prior; Y M Vigna; Sheila M. Pride

doi:10.1080/00913847.1989.11709684

Lifestyle and Environment · Physical Activity

Intense Exercise During the First Two Trimesters of Unapparent Pregnancy

Cohen GC, Prior JC, Vigna Y, Pride SM

The Physician and Sportsmedicine, 17(1), 87-94, 1989

DOI 10.1080/00913847.1989.11709684 PMID 27448004

Abstract

In Brief

Two runners who were not aware they had conceived continued their intense running regimens during the first and second trimesters of pregnancy. Both women assumed that their amenorrhea was due to endurance training. When their pregnancies were diagnosed, both women markedly reduced their training mileage during the third trimester because they feared that intense exercise might harm the fetus. Retrospective data were collected on their antenatal and intrapartum courses. Both women delivered healthy infants of normal weight. Although these two cases suggest that strenuous anaerobic exercise during pregnancy is not harmful, more studies are needed to determine if these cases are isolated.

Topics

By this author

Luteal Phase · Luteal Phase Deficiency

The influence of the menstrual cycle on muscle injuries - a systematic review and meta-analysis

Guthardt Y et al., 2026 Sci Rep Free full text on PubMed Central

This systematic review and meta-analysis examined the relationship between menstrual cycle phases and the incidence of muscle injuries in female team sport athletes, following PRISMA 2020 and PERSiST guidelines. A comprehensive search was conducted in PubMed, Scopus, and SPORTDiscus from inception to mid-January 2024. Studies were included if they examined female team sport athletes of reproductive age with regular menstrual cycles and compared the occurrence of muscle injuries across at least two menstrual phases. Studies involving hormonal contraceptive use, medications affecting the menstrual cycle or musculoskeletal system, or menstrual dysfunction were excluded. Three studies met the inclusion criteria, involving 318 participants. Meta-analysis yielded a pooled Risk Ratio of 1.18 (95% CI: 0.75 to 1.86, p = 0.46) for injury risk between the luteal and follicular phases, suggesting no statistically significant association. However, the certainty of the cumulative evidence was rated as very low due to methodological limitations, including inconsistent phase classifications and reliance on imprecise methods for identifying menstrual phases. Consequently, no practical or clinical recommendations can be made at this time. Future research employing standardised, physiologically accurate methods for classifying and detecting menstrual cycle phases is necessary to better understand the potential links between hormonal fluctuations and injury risk.

Breast Health · Benign Breast Conditions

MON-154 Breast areolar diameter in healthy menstruating women—a single cycle cross-sectional study of associations with body size and ovulatory characteristics

Baaske AV et al., 2025 Journal of the Endocrine Society Free full text on PubMed Central

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Breast Health · Benign Breast Conditions

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Wood M et al., 2025 Journal of the Endocrine Society Free full text on PubMed Central

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Hormonal Agents · Progesterone and Progestins

"SUN-109 Feasibility of Cyclic Progesterone and Spironolactone for PCOS-specific Health-Related Quality of Life—a six-month, Phase II, single arm, single center, open-label study"

Nelson K et al., 2025 J Endocr Soc Free full text on PubMed Central

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Physical Activity · Exercise and Ovulation

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Duchette C et al., 2024 International journal of women's health Free full text on PubMed Central

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Physical Activity · Exercise and Ovulation

Physical activity and incidence of subclinical and clinical pregnancy loss: a secondary analysis in the effects of aspirin in gestation and reproduction randomized trial

Russo LM et al., 2020 Fertil Steril Free full text on PubMed Central

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Physical Activity · Exercise and Ovulation

A prospective study of physical activity and fecundability in women with a history of pregnancy loss

Russo LM et al., 2018 Hum Reprod Free full text on PubMed Central

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Lifestyle and Environment › Physical Activity › Exercise and Ovulation · Pregnancy › Early Pregnancy › Miscarriage · Birth and Delivery › Birth Outcomes › Maternal Morbidity

Jerilynn C Prior

J Prior

PMID 27448004 27448004 DOI 10.1080/00913847.1989.11709684 10.1080/00913847.1989.11709684 Cohen et al. 1989, Cohen 1989

Cite this article

Cohen, G. C., Prior, J. C., Vigna, Y., & Pride, S. M. (1989). Intense Exercise During the First Two Trimesters of Unapparent Pregnancy. The Physician and sportsmedicine, 17(1), 87-94. https://doi.org/10.1080/00913847.1989.11709684