The inability of hormone replacement therapy or chronic running to maintain bone mass in master athletes

Background. Previous studies have demonstrated equivocal findings on the ef fect of chronic running on bone mass in post menopausal women. The purpose of this study was to determine the effect of chronic running alone and in c onjunction with hormone replacement therapy (HRT) on bone mineral density ( BMD) in postmenopausal women. Methods. Forty-three women [15 premenopausal 48.1 +/- .4 yrs (Pre); 13 post menopausal 57.3 +/- 2.3 yrs (Post); and 15 HRT-treated postmenopausal 56.8 +/- 1.5 yrs (PostE)] served as subjects. All were chronic runners (duration >5 yrs, >10 miles per week). BMD was determined by dual energy x-ray absor ptiometry VO(2)max on a treadmill, body composition by hydrostatic weighing , knee strength by KinCom dynamometer, and training and menstrual history b y questionnaire. Analysis of covariance with Tukey post hoc tests was utili zed to compare the groups. Results. The groups were similar in body weight, VO(2)max, years training, and miles run per week. Pre and PostE did not differ in total or spine BMD. However, Pre had greater hip BMD than PostE (.973 +/- .03 vs .876 +/- .03 g/cm(2); p < .05). As well, Pre had greater BMD of the hip (.973 +/- .03 vs .805 +/- .03 g/cm(2); p < .05), spine (1.047 +/- .03 vs .870 +/- .04 g/cm( 2); p < .05), and total belly (1.115 +/- .02 vs .996 +/- .03 g/cm(2); p < . 05) than Post. Conclusions. These results suggest that (a) chronic running + HRT is insuff icient to protect hip BMD and (b) chronic running alone provides no protect ion for bone mass in postmenopausal women.