Interview with Dr. Russell Hepple of University of Florida

Dr. Russell Hepple is a Professor of Muscle Biology in the Department of Physical Therapy, hired under UF’s preeminence campaign. He received his PhD in Physiology from the University of Toronto in 1996, and completed Postdoctoral training at the University of California San Diego in 1999.  Dr. Hepple spent the first 11 years of his academic career at the University of Calgary developing an integrative physiology research program addressing the impact of aging on skeletal muscle before moving to McGill University in 2011 where he was the inaugural Director of the McGill Research Center for Physical Activity and Health (PATH). He was subsequently recruited to the University of Florida in 2017 to join the Department of Physical Therapy, with membership in the Myology Institute and Institute of Aging. Dr. Hepple leads a lab focused upon understanding the mechanisms of neuromuscular impairment in aging and age-related diseases such as chronic obstructive lung disease, and mechanisms of healthy aging in novel populations such as world-class masters track and field athletes.

Note: You should consult with your doctor or physical therapist for recommendations on treatment. The views and opinions expressed in this article are those of Dr. Hepple and do not necessarily reflect the official policy or position of

How did you become interested in researching aging and neuromuscular impairment? 

I have always been interested in movement and sport, both from a participation and scientific standpoint. I cannot say exactly what it was about aging that intrigued me, but from the very beginning of my graduate research training I have wanted to understand the biology responsible for declining capacity for physical activity as we age, and what if anything we can do to slow that decline.

What are some of the most important things we have learned in this area of research in recent years? 

The old adage, “use it or lose it,” is highly appropriate for aging muscle and for health in general. If we stop moving, health declines. If we were sedentary and start moving, our health improves. If we keep moving, we hold onto our health longer. These are big picture things and of course, we have learned a lot about the biology of exercise in promoting health. But there remains a lot of unanswered questions. One thing that is particularly intriguing to me is that even amongst people who keep physically active, some age better than others, so it is clearly not exclusively about exercise and movement. It looks very much that some people age slower than others and this transcends even the power of physical activity.

Your most recent research focuses on age-related muscle atrophy in elderly women. What did you learn and why is this important? 

We know that some people are more affected by muscle aging than others, but our understanding of the biological processes occurring that account for this greater muscle impact is poor. Based on prior data in rodents showing that denervation, wherein individual muscle fibers lose their connection to their motoneuron, is a key cause of the acceleration of muscle atrophy in advanced age, our objective was to understand what role denervation of muscle was playing in the severity of aging impact between populations at opposing ends of the physical function spectrum in advanced age. We hypothesized that the burden of denervation would be greater in elderly individuals with poor physical function and lower in elderly individuals with high physical function. Our data supported this hypothesis and furthermore, showed that individuals with high function had a better capability for successfully reinnervating muscle fibers that had lost their motoneuron connection and this appeared to be related to higher levels of a reinnervation-promoting cytokine called fibroblast growth factor binding protein 1.

Is there anything we can do to slow muscle atrophy as we age? 

Keep moving! Being physically active is clearly the best thing to be identified thus far. Yet, as I allude to above, even those who are physically active can have variable amounts of decline, and even the most active and highest functioning among those are still affected (no one is immune to aging!).

You have also looked at neuromuscular aging as it relates to top athletes. Can an active or very athletic lifestyle impact aging? 

This is partially answered in number 4 above. Actually, our interest in the top octogenarian masters athletes sidesteps the issue of whether an athletic lifestyle can positively affect aging (but it seems clear enough that it does). Instead, because even physically active elderly exhibit a lot of person-to-person variability in capability, something that we attribute in part to a different trajectory/rate of aging, we study these folks as a model population with high function in advanced age. By doing so, our objective is to learn what kinds of biology underlie optimal physical function in advanced age. The study design necessary to isolate the effect of physical activity from these individuals is far more complex and we are not ready to take that on!

How do you choose new research projects? 

There are two main criteria: (1) What is interesting; and (2) Is it related to a clinically important question that could be funded through federal granting agencies (e.g., the National Institutes of Health [NIH])? This was the starting point for my interest in aging muscle atrophy. The criteria used now for choosing new research projects mainly relates to where the evidence suggests we need to go next to meaningfully improve our understanding.

What aspect of your research are you most proud of? 

I am curiosity driven and love research because it is exciting, dynamic, and intellectually challenging. I get easily bored by routine, but research keeps my attention because it is never the same from one day to the next. I really enjoy working with my trainees and have been very fortunate to have some truly special and gifted people work in my lab. I cannot say that I am proud of them because it was their hard work and intellectual creativity (I just try to encourage them and stay out of the way!), but I can say that I am proud for them.

What advice do you have for those interested in a career in physical therapy? 

I am not a Physical Therapist so probably not the best person to ask! Our PT department is extremely diverse and includes bench scientists like myself who have no formal training in physical therapy per se. If your career aspirations include trying to understand complex clinical problems, like the biology of muscle aging, my advice is to pick the area of science that excite you most (physiology, biology, cell biology, molecular biology, biochemistry, neuroscience, etc.), immerse yourself, read as much as you can, be critical of what you read, and take a life-long approach to learning relevant techniques to help you understand your problem of interest (science evolves; you should, too). Once you have your own lab, recruit the best young minds that you can to work on your team (and treat them well!), and have an open mind to your colleagues and collaborations. Oh, and come to a great university like the University of Florida!