Background It is hypothesized that exercise can lead to a decrease in breast cancer risk through several hormonal and non-hormonal mechanisms. The Women in Steady Exercise Research (WISER) study investigated the effects of aerobic exercise on premenopausal sex hormone levels. Methods 391 sedentary, healthy, young eumenorrheic women were randomized into an exercise intervention of 30 minutes of aerobic exercise 5 times a week for approximately 16 weeks (n=212), or into a control group (n=179). Serum levels of estradiol, estrone sulfate, testosterone, and sex hormone binding globulin (SHBG), all in the midfollicular phase, and of progesterone, in the midluteal phase, were measured at baseline and at the end of the 16-week period. Results Compared to the controls (n=153), exercisers (n=166) experienced significant increases in aerobic fitness, lean body mass, and decreases in percent body fat. There were no significant changes in body weight and menstrual cycle length between or within groups. Progesterone decreased significantly in exercisers; however, this reduction was similar to that of the control group. No significant changes between or within groups were found for any of the other sex hormones or SHBG. Conclusions In premenopausal women, 16 weeks of 150 minutes per week of moderate aerobic exercise in young women did not significantly alter sex hormone or SHBG levels. Impact Any favorable effects that moderate aerobic exercise without an associated weight change may have on breast cancer risk in premenopausal women are unlikely to be a consequence of changes in levels of sex hormones or SHBG.

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BackgroundWeight gain often occurs after breast cancer (BC) diagnosis and obesity along with sedentary behavior are associated with increased risk of BC recurrence and mortality. The primary objective of this study was to determine whether a significant weight loss, of approximately 10%, would lead to beneficial changes in biomarkers associated with cancer and/or cancer recurrence, and quality of life (QOL) in overweight and obese BC survivors.MethodsThis parallel-arm study took place in Minneapolis, Minnesota, from January 2009 until March 2010. Participants were overweight and obese postmenopausal BC survivors who had completed treatment at least 3 months prior to enrollment and who did not smoke. Twenty-one BC survivors were randomized, via a random number generator computer software, to a 1000-calorie deficit feeding and exercise intervention (CR) or a weight management counseling intervention (WM) for 12 weeks followed by a 6-week follow-up. Body weight, biomarkers, and QOL were measured at baseline, weeks 6, 12, and 18. Body composition and fitness level were measured at only two time points.ResultsTwenty-one women were enrolled into the study and 20 completed all time points. Weight loss occurred with both interventions. Body weight in CR changed from 85.5 (95% confidence interval (CI) 77, 94) kg to 76.7 (95% CI 68.1, 85.2) kg, whereas in WM it changed from 98.3 (95% CI 89.8, 106.8) kg to 93.2 (95% CI 84.6, 101.7) kg. Fitness in CR changed from 4.9 (95% CI 4, 5.8) to 6.3 (95% CI 5.4, 7.2). CR led to lower plasma levels of leptin, F2-isoprostanes, and CRP. Quality of life seemed to improve with both interventions, while sleep quality decreased only in CR.ConclusionsOverweight and obese BC survivors were able to adhere to a strict diet and exercise program, which significantly decreased body weight, increased fitness level, and improved biomarkers and QOL. However, the strict dietary intervention in CR seemed to decrease participants’ sleep quality and social relationships. Future larger randomized controlled trials should focus on behavioral modification and personalized nutrition counseling to help breast cancer survivors achieve a sustainable weight loss and fitness level.Trial registrationClinicalTrials.gov identifier: NCT02940470.

The purpose of this report is to identify factors associated with attrition and adherence of young women to a 16-week randomized aerobic exercise intervention on biomarkers associated with breast cancer risk. The exercise group was prescribed a progressive weight-bearing aerobic exercise program consisting of 30 minute workouts, 5 times/wk for 16 weeks. Adherence was calculated as the average minutes of exercise per week during participation in the study. Of the total of 212 women randomized into the exercise intervention 46 dropped out, of which 82.5% dropped out during the earlier stages of exercise suggesting that reasons for withdrawal may have been related to difficulties with initiating physical activity. Time commitment or lack of time was the primary reason for withdrawal. Drop outs reported lower physical activity at baseline than study completers (p=.0007). Although 78% of the 212 randomized participants completed the exercise intervention, only 4.7% of the participants exercised for at least 150 min/wk during the entire study period. Significant predictors of adherence were self-reported physical activity at baseline and depression scores. We conclude that predictors of adherence to exercise in our population of young women are similar to those reported for older adults. We also found that young women are more likely to exercise at moderate to vigorous intensity for 90 to 120 minutes rather than 150 minutes per week, even when participating in a highly structured exercise intervention.

Greater bone strength in female runners was attributable to greater bone area rather than density. Although male runners did not show greater bone strength, they did exhibit favorable bone geometric properties. These data further document that running has osteogenic potential.

Serial serum assays of immunoreactive FSH before, during and after a 4 h intravenous infusion of human follicle stimulating hormone (hFSH) in five healthy men revealed two disappearance rate constants with corresponding mean half-lives of 2.9 and 50.6 h. The mean distribution spaces calculated for the fast and slow component were 4.36 I and 75.9 1 respectively. The average value for the metabolic clearance rate was 17.2 ml/min and for the 225 Acta endocr. 81, 2 là I. Kinetics of human follicle stimulating hormone

It is important to know how physical activity is incorporated in women's lives to assess ways they can feasibly attain and maintain lifelong healthy practices. This study aimed to determine whether patterns of activity differed among young women whose physical activity met nationally recommended levels from those who did not. The sample was 42 women (aged 18-30 years) who had completed an exercise intervention (22 from the exercise group, 20 from the control group). Participants recorded pedometer steps and physical activities in diaries including form, duration and perceived exertion during 12 randomly assigned weeks over 26 weeks. We divided the sample into quartiles of moderate to vigorous physical activity [MVPA] to examine the composition of physical activities per quartile. Walking and shopping comprised the majority of physical activity in the lowest quartile of MVPA. In the second and third quartiles, walking and household/ childcare together comprised more than two-thirds of all activities. Only in the highest quartile of MVPA was cardio activity (not including walking, shopping and household/childcare) the largest proportion of activity; this category stood alone as varying significantly across quartiles of MVPA (p < 0.005). Among these young adult women, self-reported "lifestyle" physical activity was not sufficient to meet recommended levels of MVPA. The one-quarter who met recommended levels of MVPA did so largely through purposeful physical activities directly associated with exercise. Further research is needed to refine means of more fully measuring physical activities that women frequently perform, with particular attention to household work, childcare and shopping and to differing combinations of activities and levels of exertion by which diverse women can meet the recommended levels. The findings of this small scale study reinforce the ongoing benefit of recommending structured, planned physical activity at moderate and vigorous levels of intensity to young, healthy women to ensure they obtain the health benefits.