Every day at noon, you can find him at the Field House. He used to run two miles around the track, but since 2004 he has walked those two miles briskly, with poles. After the cardio routine, he works out with light weights. Arthur Leon, MD, has always practiced what he preaches.
This June, the world-renowned cardiologist, exercise scientist, researcher, and professor of kinesiology officially retired after 45 years at the University of Minnesota. He leaves a legacy that has altered the discipline of exercise science and the treatment of cardiovascular diseases around the world.
Arthur Leon’s story starts long before he was recruited by Henry Blackburn, colleague of the world-famous scientist Ancel Keys, to come to Minnesota in 1973 to work on a project sponsored by the National Institutes of Health (NIH).
“I was a B student in high school,” says Leon, who grew up in Miami. But at the University of Florida, he discovered a love of learning, specifically for biochemistry. In his first semester, he got all A’s except for calculus, he notes, and made the freshman honor society, Phi Eta Sigma.
“That semester was a life changer,” he says. “At the [honor society] banquet they said, ‘You know, you people are going to be the future Phi Beta Kappas.’ I couldn’t believe it. I came home, plugged in my fluorescent lamp on my desk, and attached a sign, ‘Phi Beta Leon, 4.0.’”
Four years later, he graduated summa cum laude with his BS in chemistry.
A grand plan—interrupted
Art Leon’s grand plan was to get his PhD and MD simultaneously. Then the Korean War intervened. Leon could complete his MS and MD, exempt from the draft, and fulfill his military service afterward.
The chair of the biochemistry department at Florida had recommended the master’s program in biochemistry and medical school at the University of Wisconsin, so Leon applied and was accepted. During his master’s program, he developed an interest in cardiology studying the connective tissue compound of heart valves.
Strep and the heart
“I got interested in cardiology when I was working on my master’s thesis at the U of Wisconsin looking at why strep infection can damage the heart valves. My major professor and I used to go to the Oscar Mayer plant in Madison and get on the assembly line with the butchers. They let us take the hearts. We’d remove the valves from the hearts and examine the tissues. When a person has a strep throat infection and doesn’t get antibiotics, the antibodies attack hyaluronic acid present in both the heart valves and the streptococcus surface to fight the streptococcus, but it backfires. The body doesn’t recognize the antibodies and destroys itself, creating an autoimmune condition.”
While in medical school, Leon also met and married his future wife, Gloria, who was starting a graduate program in psychology. They were introduced by a fellow medical student from Gloria’s hometown of Milwaukee.
With his MD complete, Leon decided to take advantage of the Berry Plan, which allowed him to get further training in a specialty and fulfill his service as a medical officer in the U.S. Army. He completed postdoctoral training in internal medicine at the Lahey Clinic in Boston, and in cardiology at the University of Miami School of Medicine and Jackson Memorial Hospital in Miami. He was waiting for an assignment at Walter Reed Institute of Research in 1961 when he was ordered to France. The Berlin Wall was going up.
“The American and Russian tanks were facing each other at Checkpoint Charlie,” remembers Leon, who arrived in Orleans in the Loire Valley, 70 miles from Paris. “We had a 500-bed hospital and the capability of opening up three 1,000-bed hospitals if the Russians attacked Germany. Luckily that never happened.”
Art and Gloria Leon liked France so much that he extended his assignment for a year, accepting another assignment at Walter Reed. Gloria, a psychologist, was able to teach at the University of Maryland extension, and their first child was born in a military hospital there.
Leon would remain for a total of 38 years in the U.S. Army Reserve as a cardiologist for the U.S. Medical Corps. His final tour of active duty was during Desert Shield in 1991.
The call to Minnesota
When the Leons returned to the United States in 1964, his prolific career in the new age of exercise science began.
He was on active duty in the Army stationed at Walter Reed Institute of Research, Leon says, when he teamed up with Colin Bloor, a young pathophysiologist from the University of California San Diego.
“We decided to exercise rats to see what effects it had on the heart and coronary circulation,” he says. “We saw some fantastic cardiovascular changes in rats who swam five to seven days per week.”
Their study resulted in a trove of publications, including an article in the Journal of the American Medical Association, that caught the eye of Henry Blackburn at the University of Minnesota’s School of Public Health.
Blackburn had taken over from Ancel Keys as director of the Laboratory of Physiological Hygiene, housed then at Gate 27 under the old Memorial Stadium. The lab had been the center of ground-breaking discoveries since before World War II about the relationship of nutrition and diet to the risk of cardiovascular disease.
Leon was looking at exercise and the heart, and Blackburn offered him the opportunity to work on the Multiple Risk Factor Intervention Trial (MRFIT) involving 12,000 men at high risk of heart attack due to smoking, blood pressure, and cholesterol. By that time, Leon was an associate professor at the New Jersey College of Medicine and director of the Clinical Research Center at Newark Beth Israel Medical Center. But this was an offer he couldn’t refuse.
The MRFIT (Multiple Risk Factor Intervention Trial), a national study of primary prevention of coronary heart disease, was highly influential in the development of national physical activity guidelines and the 1996 Surgeon General’s Report SAFE Study.
In 1973, the Leons moved to Minnesota. With his master’s in biochemistry and his cardiology training, Leon was assigned to manage the blood pressure clinic and lipid laboratory for the MRFIT. He also participated in a 64-item questionnaire developed by School of Public Health professor Henry L. Taylor, a renowned exercise physiologist, on leisure time and physical activity that was used in all 21 clinical centers involved in the study. But Taylor passed away before the study was completed, and Leon inherited the data set from the trial.
The young physician and exercise scientist in the Laboratory of Physiological Hygiene was clearly on the right track.
“This was just the time when other studies on the health benefits of regular physical activity were appearing,” says Leon. “It was a hot topic—physical activity or lack of physical activity, and risk of premature death and heart disease. I subsequently authored a series of papers from the 7-, 15-, and 20-year follow-ups on the 12,000 MRFIT participants.”
That included the lead authorship in 1987 of a landmark publication in the Journal of the American Heart Association on leisure time, physical activity, and reduced risk of mortality as related to coronary heart disease.
Leon’s work on the effects of exercise on rats had been attracting attention in the scientific community.
“We had shown that exercise increases coronary circulation in rodents and increases the capillary supply for each heart muscle fiber,” he says. “It improved the function of the heart.”
Leon also was the principal investigator on his first major grant from the NIH to study the effect of exercise on diabetes. The study showed that exercise could help control the disease, improving “good” cholesterol and reducing triglycerides.
Finland, 40 years and counting
Early in his career, Leon developed a relationship with the Research Institute of Exercise Medicine at the University of East Finland in Kuopio. Finland was one of the sites of Ancel Keys’ Seven Countries Study, the first to systematically examine the relationship among lifestyle, diet, and the rates of heart attack and stroke in contrasting populations. For 40 years, Leon traveled to Finland, 12 times as an invited speaker at the International Puijo Symposium. In 2012, he was inducted into the Order of the Honorary Horse Collar Knights.
Meanwhile, Leon’s friend and colleague Claude Bouchard at LaVal University in Quebec City, Canada, was exploring the idea that genetics could have an effect on the body’s response to exercise and the improvement of aerobic capacity. Bouchard discussed his plans for a research study with Leon and two other colleagues, Jack Wilmore from Texas A&M and James Skinner from Indiana University. The seeds were germinating that would grow into the largest exercise training study ever funded by the NIH, the multi-year HERITAGE Family Study.
An opportunity to grow
In the late 1980s, Michael Wade directed the School of Health, Physical Education, and Recreation (HPER) in the University’s College of Education. HPER’s mission focused on teacher education, but Wade was eager to expand it to include the study of kinesiology, the science of human movement.
Leon’s tenure and the Laboratory of Physiological Hygiene resided in the School of Public Health. The HERITAGE Family Study was in the early planning stages at a time when the School of Public Health was shifting its focus from cardiovascular to cancer research, and Wade saw an opportunity. He invited Leon to move his tenure home. Wade offered space for a lab in the newly constructed Recreation Center, on the site of the old Memorial Stadium and next to Cooke Hall. Wade liked the idea of bringing the former lab of Ancel Keys and Henry Blackburn back to its original site and merging it with the exercise science lab of HPER faculty member Robert Serfass.
“I wanted Art to come to our department, but I needed to fund him through a professorship,” says Wade.
At the time, Leon was also serving as the medical director for the Marsh, an early, preeminent wellness center in the Twin Cities founded by Ruth Stricker. After some discussion, Stricker and her husband, Bruce Dayton, offered start-up monies to create an endowed professorship if the University could match their funds.
The U of M Foundation was able to raise the money, and the Henry L. Taylor Professorship in Exercise Science and Health Enhancement made it possible for HPER to acquire Leon’s tenure line. In 1992, Leon moved into the Laboratory of Physiological Hygiene and Exercise Science (LPHES) as an endowed professor in what would become the School of Kinesiology, bringing with him the HERITAGE Family Study, by then underway.
The HERITAGE Family Study
Funding for the HERITAGE Family Study—the unprecedented, multi-year, $21 million study of exercise training—was initiated in 1992 in five research universities across the country: the University of Minnesota, Indiana University, Texas A&M, Washington University, and LSU’s Pennington Biomedical Research Center, where Claude Bouchard had moved. Leon was the principal investigator for the U of M center.
The study examined responses of biological family members to endurance exercise in order to determine the genetic component to cardiovascular and metabolic responses to aerobic exercise training. It also looked at the physiological effects of regular exercise for several cardiovascular disease and diabetes risk factors.
The world’s largest treadmill
“We had probably the world’s largest treadmill for the HERITAGE study. We could get a dozen people on it. It was built into the floor of Moos Tower. When I accepted Mike’s offer to come to the School, I tried to move this giant thing, but it was just too much. We actually offered it to the veterinarians for horses, but they said it wasn’t strong enough. The engineers took it apart and salvaged the machinery and equipment. I had pictures in my lab of visiting exercise physiologists after jogging, taking a walk on the big treadmill.”
Previous studies with identical twins and families had suggested that heredity plays a major role in determining to what degree the body adapts to an intervention, such as an exercise training program. The HERITAGE study followed 742 healthy, sedentary subjects, ages 17 to 65 years, composed of parents and their biological adult children of Caucasian and African American descent. Physiological information was assessed, and data on diet, smoking habits, level of habitual physical activity, and other lifestyle components was collected in questionnaires. The subjects were tested and exercise-trained in the laboratories for 20 weeks using the same program. The subjects were periodically re-tested.
The 13-year study had three phases: testing; data analysis and molecular genetic studies; and further refining the search for genes and mutations affecting cardiorespiratory endurance, cardiovascular disease, and type 2 diabetes risk factors.
“The study clearly showed a genetic relationship to an increase in aerobic capacity following exercise,” Leon says. “Prior to the study, everyone involved had to not exercise for six months. We got their rock-bottom level of fitness, then could compare their response when they started exercising again. We found some people who showed high levels of fitness even though they didn’t exercise on a regular basis, and we found that ran in families.”
Leon said the study found the opposite was true as well—members of the same family who were exercising regularly did not necessarily show improvement. “Some showed low fitness despite regular exercise due to their genome,” he observed. “Born couch potatoes!”
“We learned that responsiveness was about 50 percent genetic,” he says. “The importance of this is that what we call maximum aerobic capacity is the strongest predictor of how long you’re going to live if you’re healthy or, if you have disease, how long you will survive with it. That’s been something I’ve been very proud to be associated with.”
The groundbreaking HERITAGE Family Study resulted in more than 200 peer-reviewed publications on the independent contributions and interaction of genetics and exercise on the risk of cardiovascular disease and diabetes. In 2000, the study received an International Olympic Committee Award for advancing the understanding of the role of genetic and non-genetic factors in the variability of responsiveness to exercise training.
Shaping the School of Kinesiology
For more than 20 years, Leon ran the LPHES in what became the School of Kinesiology. In addition to the HERITAGE study, which ran from 1992 to 2000, a number of other significant research projects were conducted at the lab during his tenure. The Physician’s Exercise Promotion Study was a $450,000 grant funded by the American Heart Association. Dozens of grants from the pharmaceutical industry supported exploration of hypertension and blood lipid management to reduce the risk of heart disease.
Wade credits Leon with helping to shape the School of Kinesiology.
“Art’s work and presence created opportunities for us to grow the department,” says Wade. “He brought in the physiologists Marvin Bacaner and Victor Koscheyev.”
Bacaner developed bretylium, the drug that saved the life of the late President Eisenhower when he suffered a heart attack in 1955. Bretylium became a widely prescribed drug for preventing and treating heart arrhythmias and was even featured in the movie E.T. as the drug that saved the alien’s life. Dr. Bacaner eventually became chair of the University’s Department of Physiology.
Victor Koscheyev, a Russian physiologist, left his country after the fall of the Soviet Union, Wade recalls. Chief medical officer during the Chernobyl catastrophe, Koscheyev became well known for his expertise in disaster medicine as well as for his invention of garments that kept astronauts’ extremities heated in space. Koscheyev published a number of research articles with Gloria Leon, who served ten years as the director of the University’s clinical psychology graduate program.
In 2011, Li Li Ji, a leading researcher in the biochemistry of physical exercise and movement and an expert on antioxidants and free radicals in the body, was recruited to the U as director of the School of Kinesiology. In 2012, Ji succeeded Leon as director of the LPHES, while Leon continued his work as director emeritus.
A lasting legacy
If you ask Leon about his most important accomplishments, his immediate response is always the same.
“I’m very proud of my students,” he says.
He has taught thousands of undergraduate and graduate students over his long career and has advised and served on committees of many master’s and doctoral graduates. Professors Barbara Ainsworth, PhD ’87, MPH ’89, at Arizona State University and Katie Schmitz, PhD ’98, MPH ’99, at Penn State, for example, both served as presidents of the American College of Sports Medicine, and both have chaired the kinesiology departments in their universities during their careers.
Leon recalls getting Ainsworth involved in collecting data for the NIH-funded Survey of Activity, Fitness, and Exercise (SAFE) study as a graduate student.
“We were assessing physical activity via questionnaires, and she was doing a great job,” says Leon. “We wrote the research paper, and my colleague at UW-Madison, Henry Montoye, was so impressed he put her name first on the paper and mine last,” he laughed. “She always tells me this initiated her career.”
John Conrad studied with Leon for both his master’s and PhD, then got an MPH in occupational therapy at the School of Public Health and is employed by the Atomic Energy Commission in Washington state.
“He was one of the strongest men I’ve ever seen—he was on the crew that built the Canadian pipeline, then decided to go back to school,” says Leon. “He was like a member of our family. Whenever I see him, he always greets me with, ‘Hi Dad, how’s Mom?’”
Leon’s remarkable legacy is how, as part of a small, elite group of scientists and researchers, he has saved untold lives and helped educate societies on the relationship between exercise and a healthier life. He was centrally involved in discoveries and accomplishments that revolutionized cardiovascular disease research in the 20th and 21st centuries. His lifelong pursuit of the effect of exercise strategies, including strength training, on the prevention and control of obesity is today a commonly accepted prescription in the practice of medicine around the world.
And the impact of the HERITAGE Family Study continues.
“I still have subjects who contact me,” Leon says. “They want to know if we’ve done any more studies, have more data, how heredity affects habitual physical activity. The truth is, a study like the HERITAGE will never be done again.”
Leon may be retiring from the University, but his world reaches far beyond his office filled with books and files, the door always open to welcome a visitor, on the second floor of Cooke Hall. He will continue to be active in his field, he says—and the Field House.
“I try to learn something new every day,” he says. “I consider myself a student for life.”
Selected honors and awards
American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) Founding Fellow
American College of Sports Medicine (ACSM) Fellow since 1970, certified program director since 1975, two-term vice president, recipient of Citation Award in 1995 and Honor Award in 2016
American College of Cardiology and National Academy of Kinesiology Fellow
American College of Sports Medicine Fellow
William G. Anderson Award from the American Alliance for Health, Physical Education, Recreation, and Dance (now SHAPE America)
Learn more about Arthur Leon, M.D..
Story by Marta Fahrenz | Photos courtesy of Arthur Leon and the School of Kinesiology | Fall 2018