Diffee exploring how exercise
helps keep cardio, skeletal muscle healthy
Most have heard that “exercise is good for you,” and generally understand how staying active can help with everything from controlling weight and combatting health conditions, to boosting one’s mood and bolstering energy. But how, exactly, does exercise help? And to what extent can it have a beneficial effect?
“Those of us in the field of exercise physiology can sometimes fall into a trap of imagining that exercise is a cure-all for everything that’s going on in your body — and that’s not the case,” says UW–Madison’s Gary Diffee, the Department of Kinesiology’s Marsh Professor. “And when it comes to the effects of aging on cardiac or skeletal muscle function, we still have a lot to learn.”
For years, Diffee -- who arrived on the UW–Madison campus in 1992 to conduct post-doctoral work before joining the Department of Kinesiology as a faculty member in 1997 — focused his research on basic muscle physiology and exploring how muscles change and adapt to things like aging, disease and exercise.
One study he conducted examined how heart muscles of rats that routinely exercised differed from sedentary hearts. The results showed that, while there were some differences with exercise, the effects of exercise on heart function were not dramatic. This isn’t surprising, Diffee now says, considering that the heart is pretty good at what it does. Even in people who don’t exercise, it beats about once per second every second one is alive.
So Diffee started to ponder, if exercise doesn’t make muscles significantly stronger, what is it about staying active that keeps people healthier and helps slow the aging process in both cardio and skeletal muscle?
Recently, Diffee and those working with him in the Virginia Harrison-Marsh and William Hector Marsh Center have started more closely examining the metabolic processes, or the way in which cells provide energy for contraction. In particular, Diffee explains that there is growing evidence that an organelle in cells called the mitochondria, which provides energy for the cell to operate, changes as one gets older.
Furthermore, studies conducted by Diffee and those in the Marsh Center – which is dedicated to promoting research activities and education in the area of physical activity, exercise and movement — indicate exercise plays a role in minimizing age related changes in mitochondria, which could help explain why exercise slows the decline of muscle function.
“We’re still asking some very fundamental questions and trying to figure out the basics of the processes going on in these cells,” says Diffee. “Every time you find some answers in research, you then have a whole new series of questions worth looking into.”
Diffee can’t help but let out a laugh while describing his latest research, noting, “The professors I had as an undergrad would find it very surprising that I’m a lab researcher.”
Diffee explains that as an undergraduate, he struggled with biology and started to associate success in that coursework with being able to memorize various scientific terms and concepts.
So in addition to his work in the lab, Diffee also is committed to being a great teacher. He explains to his students how science and biology are less about a series of facts to be memorized and more about a set of mysteries to be solved. Diffee again this fall is teaching an introduction to kinesiology course to a cohort of UW–Madison freshmen enrolled in a First-Year Interest Group titled, “Physiology of Human Performance.”
“I want to bring this idea of thinking creatively and problem solving and being a good detective — things I was missing as an undergraduate — to both my work in the lab and to my students as a teacher.” says Diffee.