Performance in Motion, Volume 1, Number 2, Fall 1993

Research Report from the Exercise Physiology Division

by Dr. Jeanne Foley

With the departure of faculty member Carol Rodgers (to a faculty position at the University of Toronto in her native Canada) and the dismantling of the existing Center for the Study of Human Performance at Erickson Hall, the Exercise Physiology area finds itself in a state of flux this fall. However, with changes come the opportunity to grow in new directions, and that is what we are in the process of doing. Efforts are underway to find a new home for the CSHP lab, and discussions are being held with various groups on campus regarding cooperative efforts in this area. We hope to have a new (and newly outfitted!) location and also a new exercise physiologist on staff before the start of the next academic year. In the meantime, Dr. William Heusner has graciously consented to make a temporary return from his retirement to help with the advising of Dr. Rodgers' remaining graduate students, and Dr. Jon Robison (Ph.D. in Exercise Physiology and Nutrition, MSU, 1991) is helping out with some of the teaching load. Dr. Manny Felix also joins us on a postdoctoral fellowship in conjunction with the College of Natural Science to study the relationship of bone density to physical activity and estrogen levels in pre- and post-menopausal women.

Despite the setback in relocating the lab, there is still considerable research activity ongoing in the area. My primary research focus has been in the area of applications of magnetics resonance imaging (MRI) to the study of exercise responses. Currently most of this research is being conducted at the MSU Clinical Center in cooperation with the department of radiology and physiology. My future plans are to integrate fitness testing and body composition capabilities into my projects, but for the moment I am staying busy with two ongoing and several planned projects in the MRI area. 

One of the ongoing projects is of particular relevance to this newsletter, as it not only involves PEES undergraduate and graduate students in various degrees of observation and participation, but also is using several retired PEES faculty and/or their spouses as subjects. This particular study involves the use of a brand new MR technique for imaging of the peripheral vasculature and measuring blood flow to leg muscles before, during, and after exercise. As expected due to the decrease in arterial compliance (increase in stiffness) with age, the results from the 12 subjects tested so far have shown that individuals over age 65 have a decreased capacity to increase muscle blood flow in response to exercise compared to young adult subjects. The unexpected outcome was that the older subjects had a much higher resting blood flow to their muscles than did the younger subjects, which may be an adaptation to the decreased dilation
capacity in the older subjects. If this contrast holds true across the subjects remaining to be tested, this discovery could open a new avenue of study in the field of physiological adaptations to aging. My presentation of the preliminary results at the American College of Sports Medicine conference in Seattle in June generated much interest and discussion as well as some intriguing new perspectives on the project.

My other ongoing project is geared towards using the MR angiographic technique described above to examine blood flow in muscles during and after isometric (static) contractions. Previously used methods of blood flow measurement, including Doppler ultrasound and plethysmography, are not as sensitive as MR to blood flow in the deeper vessels, so I am expecting this project to uncover some new information as well.

Projects planned for the immediate future include a collaborative NASA project with PEES doctoral student Glenna DeJong and her colleague Dr. John Davis from Alma College to study the effects of simulated weightlessness on muscle blood flow. Another cooperative study will involve our biomechanics division, as Dr. Dianne Ulibarri and her colleagues at the Biomechanics Evaluation Laboratory will be working with our MR group to look at the use of MR imaging to determine inertial moments of body segments. I am also applying for research grants from the Diabetes Education and Research Foundation, the America Federation for Aging Research, and the America Heart Association for funding to extend these MR techniques to populations of particular interest to each of these groups. Eventually I hope to study the effects of fitness on these vascular responses, which is where the rebirth of the CSHP lab will help immensely. Another potentially exciting area of study is the use of MR images to determine body composition in terms of the percentages of fat, muscle, and bone tissue in the body. Such a project would require parallel validation studies using the established technique of hydrostatic
weighing, and a new underwater weighing tank is on the "wish list" for the new facility.

The bottom line is, things are changing down here in the exercise physiology area, but some exciting new possibilities are on the horizon. Stay tuned for more news, and give me a call at 355-4735 if you'd like to come in and see what we're doing or (better yet!) participate in one
of our studies.