EXERCISE-ASSOCIATED CANCELLOUS BONE CHANGE: POSITIVE EFFECT OF OVULATION 1116

M A Petit; Jerilynn C Prior; Susan I Barr; Y M Vigna

doi:10.1097/00005768-199705001-01114

Bone Health · Bone Mineral Density

EXERCISE-ASSOCIATED CANCELLOUS BONE CHANGE: POSITIVE EFFECT OF OVULATION 1116

Petit MA, Prior JC, Barr SI, Vigna YM

Published May 1997 Medicine & Science in Sports & Exercise, 29(Supplement), 196

DOI 10.1097/00005768-199705001-01114

Abstract

Current concepts suggest that normal estrogen levels are necessary for exercise to have an osteogenic effect on bone. In a population of running and sedentary women Prior et al. (NEJM, 1990) have shown that consistent ovulation is necessary to prevent spinal cancellous bone loss. Change in spinal bone mineral density was measured by quantitative computed tomography (QCT) in running and sedentary women over one year, along with prospective documentation of dietary, menstrual cycle, hormonal, and exercise variables. Of the 66 women studied only 12 remained ovulatory throughout the year. Forty-two women were runners of which 6 were consistently ovulatory. We hypothesized that ovulation would interact with an exercise effect on cancellous bone. Analysis of the 42 runners showed an average loss in bone of 1.8%. Luteal phase index (r = 0.509) and average progesterone (r = 0.381) were correlated with change in QCT, but not estrogen, calcium, or any other hormonal, dietary, or morphometric variable. There was a negative association between change in QCT and number of km run/week (r = -0.319). In the 12 consistently ovulatory women, average cancellous bone increased in runners(≈2%) and decreased in nonrunners (N) by ≈1% (seefig.). These data are the first to show an increase in purely cancellous bone with moderate levels of aerobic activity. The results suggest that the presence of consistently ovulatory cycles, and thus progesterone in addition to estrogen, may be necessary for an osteogenic effect of low impact exercise (running) on cancellous bone.

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

Tanner Breast Stage 3 (TB3, at menarche) and Tanner 5 (TB5, once ovulatory cycles established), despite being similar with an “upstanding” nipple, are different. Evidence suggests that steady and high ovulatory-level progesterone exposure accounts for the larger areolar diameter in TB5. Progesterone levels indicate whether the menstrual cycle is ovulatory and have crucial implications for women’s reproductive, metabolic, cardiovascular, and bone health. However, few data show average areolar diameter in regularly cycling women in whom SES, body size, and reproductive variables have been documented. As a step towards better understanding the role of areolar diameter in reflecting estradiol-progesterone balance, this study aims to document the average mean bilateral lateral areolar diameter (AD) in a cohort of regularly menstruating, premenopausal women in whom ovulation was documented in one cycle. We also aim to describe relationships between AD and demographic, anthropometric, and reproductive/ovulation variables. Women were eligible if aged 19-35 years with about month-apart cycles and no exogenous hormone use in the last 3-months. Participants completed one cycle with a daily Menstrual Cycle Diary© (cycle length, CL) and first morning temperatures for Quantitative Basal Temperature© (QBT©) ovulation analysis (normal luteal phase length ≥10 days). Questionnaires gathered SES, ethnic, general health, and reproductive characteristics. Bilateral horizontal areolar diameters were measured by a woman researcher with the participant supine in a warm room. From February 2020 to September 2022 (during the SARS-CoV-2 pandemic), 73 women from Metro Vancouver, British Columbia participated. Women were of median (min-max) age 30 (19-35) years, BMI 24.5 (17.1-41.4) and most identified as White (61.6%) with a median of 16 years of education. Median CL was 29 days (n=65) and QBT data showed 39.3% were normally ovulatory, 34.4% had short luteal phases and 26.2% were anovulatory. Median within-woman bilateral AD was 3.85 (2.35-8.00) cm. Left AD exceeded right (L 3.8 [2.3,8.2]; R 3.7 [ 2.4,7.8]; P=.003). Larger AD (≥3.85cm) was associated with greater body size (BMI r=.534), weight and waist circumference. However, earlier age at menarche (P=.02) was also significantly associated. No other reproductive variables (cycle length, luteal phase length, parity, ever use of CHC) were related to AD before body size adjustments. This study is the first to document, and describe demographic, anthropomorphic and reproductive associations with, AD in community dwelling, regularly cycling, premenopausal women. Future steps will determine the most influential of the anthropometric variables; adjustment for these will facilitate assessments of associations with ovulation related characteristics.

Breast Health · Benign Breast Conditions

SAT-128 Prospective 1-year Menstrual CycleBreast Tenderness and Swelling Experiences—data from healthy regularly cycling women initially proven normally ovulatory on two consecutive cycles

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

Breast tenderness and swelling are associated with premenstrual symptoms but have not been well described in healthy, normally cycling women with known ovulatory status. There are documented negative health risks (in bone, the cardiovascular system and cancers) in association with ovulatory disturbances within normal-length cycles. Identifying breast changes across a predictable, month-apart cycle but with Subclinical Ovulatory Disturbances (SOD, short luteal phase [<10 days] and anovulation (with normal estradiol but lower or absent progesterone levels) could advance our understanding of menstrual cycle physiology, women’s health education and identification of those with chronic SOD who may benefit from cyclic progesterone therapy. Our objective was to determine whether within-woman breast tenderness and swelling experiences differed between normally ovulatory and ovulatory-disturbed cycles. In this 1-year prospective observational study, we examined daily breast tenderness (0-4) and swelling (1-5 change from usual = 3) experiences recorded via the Menstrual Cycle Diary© over ≥8 cycles (mean=13/woman) in 53 women. Ovulatory status was documented by the twice-validated Quantitative Basal Temperature© (QBT©) analysis. Cycle and ovulatory data were previously reported (Prior NEJM, 1990); Diary data were unreported. Participants were healthy, community-dwelling women, mean age 34 (32.4:35.5 years), BMI 22.0, primarily White, and about two-thirds were runners (for health or were marathon-training). Comparison of breast parameters in all normally ovulatory (n = 495) vs all SOD cycles (n = 199) (mean cycle length 28.1 [27.5-28.8 days]), showed significantly higher Breast Tenderness Score [intensity X days; 6.0 (range 1.0, 14.0) vs. 3.0 (0.0, 11.0) (P = .001)] and increased breast size [4.0 (2.0, 4.0) vs. 4.0 (0.0, 4.0) (P = .034]) in normally ovulatory cycles. However, in within-woman analysis (n = 47 women with both normally ovulatory and SOD cycles), breast tenderness/swelling did not significantly differ by ovulatory status. We plotted all ovulatory cycles (n=676) centred on ovulation; this revealed parallel timing of increases in breast tenderness and swelling in the late luteal phase. These 1-year prospective data documented that mild breast tenderness and swelling occurred before flow in cycles with normal ovulation; symptoms were less in SOD cycles. Breast changes were totally absent during the follicular phases.

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

Polycystic ovary syndrome (PCOS) is an endocrine-metabolic disorder that significantly decreases health-related quality of life (HRQoL). Combined hormonal contraceptives (CHC) are standard-of-care for PCOS but do not mitigate the neuroendocrine cause nor women’s primary concerns. Treatment options need expansion. We hypothesized cyclic oral micronized progesterone (CyclicP4) and spironolactone (Sp) would improve HRQoL, decrease LH, and acne. This Phase II, open-label single-arm pilot study evaluated the 6-month cyclicP4 and Sp treatment feasibility and safety in androgenic PCOS. Our primary outcome was within-woman change in PCOS-HRQoL (PCOSQ). No sample size calculation was possible; 40 was considered feasible. Eligible women were 19-40 years with physician-diagnosed androgenic PCOS. Exclusion criteria included HbA1c > 6.4%, use of metformin or CHC in the last month. Participants received progesterone (300 mg/bedtime 14 days/month); spironolactone (200 mg/day) began in cycle two. Adherence was tracked daily (Menstrual Cycle Diary©) and by pill counts. Safety was assessed by post-study potassium (K+). Feasibility by women’s post-trial treatment intention. PCOSQ, serum LH, calculated bioavailable testosterone (cBAT), HbA1c, hsCRP, and AMH were measured at baseline and trial end. We also assessed perceived acne and sleep changes (-5 to +5), K+ and therapy intent at study end. Six-month change by paired t-test or Wilcoxon signed-rank assessed P < .05 as important. Of 109 expressing interest, 41 enrolled, 36 began therapy (5 did not), and 26 provided final questionnaire data (19 with complete lab data). Completing women were mean age 29 (SD 4.9) years, BMI 30.3 (8.1), 61.5% White and 73.1% with university degrees. Total PCOSQ scores within-woman increased from 3.5±1.0 to 4.9±1.1 (95% CI 3.1-3.8, 4.6-5.3; P<.0000001). Each PCOSQ domain significantly improved (at least P<.001) as did acne and sleep. Weight was unchanged but waist circumference decreased 1.1 cm (NS). LH, cBAT, and AMH each decreased: LH 10.0±5.4 to 8.5±5.2 IU/L (95% CI 7.6-12.3, 6.3-10.8; P<.4), cBAT 0.7±0.4 to 0.6±0.3 nmol/L (0.5-0.9, 0.5-0.8; P<.2), and AMH 10.5±6.5 to 9.7±5.7 ng/ml (7.4-13.7, 7.0-12.4; P<.4). hsCRP remained unchanged (2.8±3.3 to 2.7±3.6 mg/L; P<.8) as did HbA1c (5.2±0.3 to 5.2±0.3%; P<.0). K+ remained within the normal range (3.5-5.0 mmol/L) at final testing (mean 4.0). Two allergic responses to spironolactone and one frequent flow/religious practice led to discontinuation. Feasibility was confirmed and participants strongly preferred continuing therapy (median Likert score=6/7, P<.0001) CyclicP4 and Sp for 6-months was feasible and significantly improved HRQoL in a non-medicine-seeking community women cohort with androgenic PCOS. Though the small sample size limited generalizability, findings are promising. A larger randomized trial comparing CyclicP4 vs. CHC is warranted.

Related research

Bone Mineral Density · Peak Bone Mass

Running and ovulation positively change cancellous bone in premenopausal women

Petit MA et al., 1999 Med Sci Sports Exerc

Exercise is understood to exert positive effects on bone. However cancellous bone has not been shown to increase with exercise. Previous results of our 1-yr observational prospective study in ovulatory women related 20% of the change in cancellous spinal bone mineral density (BMD), measured by quantitative computed tomography (QCT), to luteal phase length (the time from ovulation to menstruation, LL). The 66 women who documented exercise daily included normally active women (N = 23) and those who ran consistently or were increasing running in preparation for a marathon (N = 43). Exercise did not affect BMD change in the women as a whole. We re-evaluated those data to determine whether exercise-related effects on spinal cancellous BMD change in regularly cycling premenopausal women were related to ovulatory characteristics. The potential relationship of exercise to BMD change was reanalyzed by stratifying women into tertiles according to average LL documented by quantitative basal temperature analysis. Repeated-measures ANOVA indicated independent positive effects of both luteal length (P = 0.001) and activity (P = 0.041). The 11 runners with LL > 10.9 d had a nonsignificant 0.5% increase in lumbar BMD while the 15 who averaged short LL (<9.9 d) experienced a significant 3.6% loss. In the runners as a group, however, kilometers run per week was negatively related to BMD change throughout (r = -0.347, P = 0.024). These data are the first to indicate that, in women with regular cycles, luteal length and exercise independently and positively affect change in spinal cancellous BMD.

Bone Mineral Density · Measurement

Ovulatory premenopausal women lose cancellous spinal bone: a five year prospective study

Prior JC et al., 1996 Bone

Healthy premenopausal women with regular cycles are believed to be increasing or maintaining bone density. However, few studies have prospectively documented spinal cancellous bone, the bone that changes rapidly in response to reproductive hormones, in this population. Furthermore, our previous one-year study documented that 24% of the one-year bone change by quantitative computed tomography (QCT) was related to subclinical ovulatory disturbances (short luteal phase and non-ovulation) in the presence of regular menstrual cycles. The purpose of this study was to document the cancellous bone change over five years in this initially ovulatory, premenopausal cohort of 66 healthy women. Thirty-seven women, who continued to be premenopausal and have regular cycles, completed this five-year study. Those enrolled differed only by being older and weighing less than those who could not be contacted (n = 19) or who declined to participate (n = 10). Documentation of current ovulatory characteristics was obtained for at least three cycles in 27 women. At the five-year assessment, the volunteers were 40.6 (range 26-47) years old, weighed 58.5 (41-77) kg, and were 160.9 (149-174) cm in height. All were premenopausal, healthy, nonsmokers with regular menstrual cycles (mean 27.7, range 24-33 days). Six women with intervening events (such as pregnancy or use of oral contraceptives) had interval (12 to 60 months) QCT changes similar to the remaining 31 (-7.98 vs. -4.92 mg/cm, p = 0.1, respectively). Mean five-year QCT was 143.0 +/- 20.2 mg/cm, whereas the initial mean value was 151.9 +/- 20.1 mg/cm. Significant QCT loss over five years (-8.9 +/- 6.2 mg/cm) (95% Cl -6.9 to -11.0) correlated with QCT change in the first year (r = 0.629, p < 0.001). First-year change was not related to the subsequent four-year interval change (r = -0.056, p = 0.74), however. Five-year QCT change was not related to age, weight, osteoporosis family history, estimated calcium intake, or exercise, but did correlate with year one luteal index (luteal/cycle length) (r = 0.339, p = 0.043). Significant cancellous spinal bone loss occurs in healthy, ovulatory premenopausal women, and is influenced by subclinical disturbances of ovulation.

Hormones and Bone · Estrogen and Bone

Spinal bone loss and ovulatory disturbances

Prior JC et al., 1990 N Engl J Med

Osteoporosis develops in women with estrogen deficiency and amenorrhea who lose bone at an accelerated rate. It is not known to what extent bone loss differs between ovulatory women with regular menstrual cycles who are training intensely and those who are sedentary. We measured the density of cancellous spinal bone from the 12th thoracic vertebra to the 3rd lumbar vertebra by quantitative computed tomography on two occasions one year apart in 66 premenopausal women 21 to 42 years of age. All the women had two consecutive ovulatory cycles immediately before entering the study. Twenty-one women were training for a marathon, 22 ran regularly but less intensively, and 23 had normal levels of activity. The lengths of the women's menstrual cycles and luteal phases, diet, exercise levels, and hormonal levels were also determined. We defined ovulatory disturbances as anovulatory cycles and cycles with short luteal phases. The mean (+/- SD) spinal bone density in the 66 women decreased 3.0 +/- 4.8 mg per cubic centimeter per year (2.0 percent per year) (P less than 0.001). Amenorrhea did not develop in any woman during the year of observation (only 2.7 percent of the cycles were greater than 36 days long). Ovulatory disturbances occurred in 29 percent of all cycles, however. Bone loss was strongly associated with these disturbances (r = 0.54, 24 percent of the variance). The 13 women who had anovulatory cycles lost bone mineral at a rate of 6.4 +/- 3.8 mg per cubic centimeter per year (4.2 percent per year). The women training for a marathon had menstrual cycles similar to those of the women in the other two groups. Decreases in spinal bone density among women with differing exercise habits correlated with asymptomatic disturbances of ovulation (without amenorrhea) and not with physical activity.

Hormones and Bone · Estrogen and Bone

Negative spinal bone mineral density changes and subclinical ovulatory disturbances--prospective data in healthy premenopausal women with regular menstrual cycles

Li D et al., 2013 Epidemiol Rev

Subclinical ovulatory disturbances (anovulation or short luteal phases within normal-length menstrual cycles) indicate lower progesterone-to-estrogen levels. Given that progesterone plays a bone formation role, subclinical ovulatory disturbances may be associated with bone loss or less than expected bone gain. Our purpose was to perform a meta-analysis of prospective studies in healthy premenopausal women to determine the overall relationship of subclinical ovulatory disturbances to change in bone mineral density. Two reviewers independently identified from serial literature searches 6 studies meeting inclusion criteria: a 2-year study in 114 young adult women, 2006-2009, Vancouver, Canada; a 2-year study in 189 premenopausal women, 2000-2005, Toronto, Canada; a single-cycle study in 14 young women, 1996-1997, Melbourne, Australia; an 18-month study in 53 women, 1990-1995, Santa Clara, California; a 4-year study in 27 women, 1988-1995, Vancouver, Canada; and a 1-year study in 66 women, 1985-1988, Vancouver, Canada. This meta-analysis included a combined sample size of 473 observations in 436 premenopausal women studied over 1-4 years and aged 14-47 years. The percentage of women with ovulatory disturbances varied significantly from 13% to 82%. Women with more frequent ovulatory disturbances had more negative percentage changes in spine bone mineral density (weighted mean difference = -0.86; P = 0.040) for random-effects analysis. There was significant heterogeneity among these 6 studies (I(2) = 80%). In summary, these data show that regularly menstruating women with more frequent ovulatory disturbances experience more negative changes in bone (approximately -0.9% per year). These cycles with silent estrogen/progesterone imbalance may be clinically important.

Bone Health › Bone Mineral Density › Measurement · Lifestyle and Environment › Physical Activity › Exercise and Ovulation · Reproductive Endocrinology › Ovarian Hormones › Progesterone

Susan I Barr, Jerilynn C Prior

Sue Barr, S Barr, J Prior

DOI 10.1097/00005768-199705001-01114 10.1097/00005768-199705001-01114 Petit et al. 1997, Petit 1997

Cite this article

Petit, M. A., Prior, J. C., Barr, S. I., & Vigna, Y. M. (1997). Exercise-associated cancellous bone change: Positive effect of ovulation 1116. Medicine & Science in Sports & Exercise, 29(Supplement), 196. https://doi.org/10.1097/00005768-199705001-01114