The Exercise Endocrinology Laboratory offers laboratory and clinical experiences to students interested in the interactions of exercise and nutrition and on the effects of exercise on energy regulation and hormone secretion in humans. Experiences are driven by basic questions, but the work involves working with human subjects and dealing with the applications of theory to practice. Experiences can include interactions with study subjects, assessment of their dietary intake, aerobic fitness, and energy balance, entry of data into databases, working with blood samples and doing metabolite and hormone assays.

Dr. Katarina Borer studies the effects of endurance exercise training on animal growth and human growth hormone secretion, as well as on energy regulation and fat loss. She investigates the effects of exercise training on growth and energy regulation through studies of the roles of nutrition and hormones in these phenomena. In her earlier studies, Borer used golden hamsters because they voluntarily run marathon distances each night. In her present studies, she studies post-menopausal women because they are at risk of developing obesity, diabetes, and coronary heart disease, and have low levels of growth hormone. Her studies explore whether exercise training in the form of walking when carried out at different intensities can affect insulin sensitivity (and risk of developing diabetes), growth hormone secretion (and maintenance of lean body mass and control of abdominal fat), body fat level and regional distribution, and several risk factors for developing coronary heart disease (hypertension and blood clotting factors).

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Endocrine effects of training exercise intensity in postmenopausal women
	Incidence of diabetes has been rising in the past decade in part because of increased incidence of obesity and high consumption of sugar. Although diabetes is not the leading cause of death in postmenopausal women, when it develops it is associated with serious disabilities that include deterioration of vision and of circulation in the limbs and in the kidney. While most of us tend to associate growth hormone secretion only with growth in height in childhood and during adolescence, this hormone is an important regulator of body fat (especially in abdomen) and protector of lean body mass. GH secretion declines precipitously with age but can be increased with exercise. The purpose of the study is to define optimal exercise intensities for increasing insulin sensitivity and growth hormone secretion. We measure additional hormones in the blood samples we collect in order to see whether they are affected by exercise or any fat loss that takes place.
The effect of training intensity on the heart-rate and blood pressure variability in postmenopausal women
	The goal of this study is to see how 15 weeks of exercise training in the form of walking (3 miles a day, five days a week) at different speeds affects several risk factors for developing coronary heart disease (CHD). While most of us tend to associate high risk of CHD with men, CHD is actually the number one cause of death in both men and women above age 54. The risk factors that we focus on in this study are: • heart-rate variability (which decreases with age) • suppleness (distensibility) of arteries which decreases with age, and contributes to hypertension (this is done with the endothelial function test) • blood-pressure variability (which can progress to hypertension) • plasma lipids (HDL,LDL, triglycerides) • blood clotting factors (which cause heart attacks and stroke) • body fat (which influences most of the above factors, measured by bioimpedance and anthropometric methods) • aerobic fitness (done with a walking treadmill test).

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Faculty:   Katarina Borer, Ph.D. (katarina@umich.edu), Director Graduate Student(s):   Elizabeth Wuorinen, M.S., CHFI, CSCS (ewuorine@umich.edu), doctoral student   Katrina Fogleman, M.S., (kfoglema@umich.edu) doctoral student Collaborations:   Josephine Kasa-Vubu, M.D. (jzkv@umich.edu), UM Medical School [Pediatrics]   Maryfran Sowers, Ph.D. (mfsowers@umich.edu), UM School of Public Health [Epidemiology]   William Fay, M.D., (wfay@umich.edu) UM Internal Medicine [Cardiology]   Robert Brook, M.D. (robdbrok@umich.edu), UM Internal Medicine [Hypertension]   Sanjay Rajagopalan, M.D., (srajagop@umich.edu), UM Internal Medicine [Hypertension]   Virginia Uhley, Ph.D. (vuhley@umich.edu), UM School of Public Health [Environmental Health Sciences]   Franz Halberg, M.D., Halberg Chronobiology Center, Minneapolis, MN   Germaine Cornelissen, Ph.D., Halberg Chronobiology Center, Minneapolis, MN

Dr. Borer's Personal Home Page, with information pertaining to her current studies www.umich.edu/~katarina

Center for Exercise Research www.kines.umich/research/cxr/cxrindex.htm

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