Exercise Physiology on the Riverfront

Two professors from the Louisiana State University Health Sciences Center’s School of Allied Health Professions gave their students a first-hand experience they would not forget.

Dennis R. Wissing, PhD, RRT, facilitates a postexercise discussion with students.

The Louisiana State University (LSU) Health Sciences Center’s School of Allied Health Professions in Shreveport, La, offers six allied health programs, including cardiopulmonary science (CPS), clinical laboratory science (CLS), physician assistant (PA), communication disorders (CD), occupational therapy (OT), and physical therapy (PT). The first three programs offer an undergraduate degree while the latter three are graduate level programs. Despite offering two levels of education, there is a school-wide sense of collaboration manifested by an interdisciplinary approach to teaching shared by the faculty.

The school’s PT program offers a clinical master’s degree. Students complete 28 months at LSU Health Sciences Center to earn their MPT. The CPS program, which includes professional training in respiratory care (registry level) and cardiovascular technology (invasive and noninvasive cardiac diagnostics), offers a baccalaureate degree. Although each of these programs stands alone, a collaborative spirit among program faculty and students exists. Sharing faculty between the programs exposes students to a variety of instructors. For example, for a number of years, I have cotaught the cardiopulmonary rehabilitation course in the PT curriculum with Jim Bellew, EdD, PT, and have been a lead instructor in the Department of Physical Therapy’s exercise physiology course. Likewise, several of the PT faculty have taught body mechanics and transfer techniques in a respiratory care fundamentals course.

LSU Health Sciences Center’s CPS students enroll in a cardiopulmonary physiology course in the second semester of their junior year. It has been a typical lecture/discussion-type course. In order for students to get a good grasp of cardiopulmonary physiology on which to build knowledge, I emphasize topics such as mechanics of ventilation, pulmonary blood flow, hemodynamics, how the lungs and heart work together to provide oxygen transport to body tissues, and the effects of exercise on cardiopulmonary function. It has been my experience that if students understand key concepts in exercise physiology such as how the cardiac system limits exercise capabilities, effects of training on aerobic fitness, and how the body adapts to long-term training, then they generally develop a good understanding of cardiopulmonary physiology. However, because I was not satisfied with the level of student understanding, I decided a novel approach to teaching this course was needed.

An Exercise Experience Is Born
During the past semester, while teaching a cardiopulmonary physiology course, I was also coteaching with Bellew in the Physical Therapy Department. We were teaching the second-year master’s of physical therapy students a course in cardiopulmonary rehabilitation. This course included a review of exercise concepts in healthy states and the impact of lung and heart disease on exercise response.

Bellew and I agreed to try a different approach for teaching course concepts. He also recognized that many students demonstrated gaps in their knowledge and practical understanding of exercise physiology. Since both PT and CPS students would potentially work with patients with lung disease, developing a hands-on exercise experience that assisted in understanding the impact of lung disease on exercise became our goal.

Bellew and I had an idea for an educational experience in which both groups would participate. The groups received classroom instruction on normal cardiopulmonary response to exercise and how lung and heart disease altered this response. Lecture material included information on how the pulmonary system responds to a decrease in lung and chest wall compliance and an increase in airway resistance. It was our belief that both groups would encounter patients with reduced chest wall compliance, which is seen in patients with kyphoscoliosis or a disease associated with an increase in airway resistance such as asthma.

Shelly Mercer, PT (left), and Heide Birdsall, CPS, finish the three-mile run while Beth Mathews, PT, who had already finished the run, watches.

Following these series of lectures, Bellew and I met with both groups of students early one day in the fall at the Shreveport Riverfront Park and Jogging Trail. The park has a 10-mile jogging trail, which parallels the Red River. Students were instructed to prepare to walk or run at least three miles along the jogging trail. Any students with physical limitations were given the option to decline but were to assist in other ways such as distributing water and offering others encouragement.

The students were given the choice of walking or running the first 1.5 miles under normal conditions. About three quarters of the group jogged while the others walked briskly. Water was provided at the completion of this first leg of the exercise. The students were then randomly divided into two groups. Group one had a tightened heavy leather belt placed around their mid-chest wall. Group two inserted an inch-long, half-inch-diameter PVC tubing into their mouth (see picture). Each student was then encouraged to complete the latter 1.5 miles the same way they had come.

During the entire exercise experience, Bellew and I encouraged the students to pay attention to their cardiopulmonary response to exercise. Emphasis was placed on being aware of the work of breathing and fatigue levels. I ran along with the group observing their physical response and monitored participants for any adverse effects.

After the students completed the latter 1.5 miles, they were allowed to recover and rest. Once adequate hydration and rest were provided, I distributed a short handout on basic principles of how the body responds to exercise in healthy states and with lung disease. This teaching aid, which included graphs, figures, and some text, helped encourage the discussion that followed.

Discussion
We discussed each student’s physical experience on both legs of the exercise (see picture on page 10). It was Bellew’s and my hope that the students would learn firsthand a number of key concepts in exercise physiology, such as how the body initially adjusts to increasing work, which is an increase in heart rate, then an increase in tidal volume, followed by an elevated respiratory rate. Most students have an alternative conception that the respiratory system increases its rate and depth before the cardiovascular system adjusts itself. In addition, students tend to think that the respiratory system is the limiting factor in exercise capabilities. One of the key concepts that Bellew and I wanted to get across was the role of the cardiovascular system in limiting exercise. We also encouraged students to pay attention to the onset of fatigue. The sense of fatigue or need to stop exercising varies from person to person. Often people stop at a point due to habit or lack of motivation to continue and not simply because of a depletion in glycogen stores and blood glucose, which can occur with moderate-to-heavy exercise. It was noted in our discussion that many of the participants could go further than they thought they could. During the last 1.5 miles, students were encouraged to pay attention to how their bodies responded to an artificially induced workload.

As I participated by running with the groups on both legs of the exercise, I observed many of the students on the latter leg seemed to be in obvious distress due to the chest wall restriction (chest belt) or obstruction to airflow (PVC pipe). Those with the chest wall restriction appeared to have the highest work of breathing while those breathing through the straw attempted to slow down their pace and breathing rate. Bellew and I observed that the students with chest wall restriction tended to breathe fast and were quite tachypneic, especially at the end of the third mile. The students breathing through the straw tended to slow their pace and exhibited considerable effort to breathe. Despite the increased effort to walk or jog, they were all able to complete the exercise.

It was apparent from the postexercise discussion that the students had a new appreciation for dyspnea and increased work of breathing. They experienced the expected responses we had discussed in the classroom. As we pointed out in the lecture, our response to exercise with a decrease in chest wall compliance is an elevated respiratory rate or panting, while an increase in airway resistance causes people to slow down their rate and inspiratory flow. Seeing these results firsthand helped these students conceptualize many of the key ideas we discussed in class.

This exercise allowed two academic disciplines within the same school to join together to learn about exercise physiology. Both groups of students developed an understanding of how patients with lung disease respond to exercise. Employing hands-on exercises such as this can result in participants gaining an awareness of how the patient feels, resulting in better patient care. The exercise was well received by the students, and Bellew and I are planning to repeat this exercise each year.

Dennis R. Wissing, PhD, RRT, is professor and head of the Department of Clinical Sciences, and program director of the Cardiopulmonary Science Program; and Jim Bellew, EdD, PT, is assistant professor, Department of Rehabilitation Sciences, and the Physical Therapy Program, Department of Physical Therapy, both at LSU Health Sciences Center, School of Allied Health Professions, Shreveport, La.