Kristen R. Howard and Olalla Prado-Nóvoa: Does more running burn more calories? Research study volunteers needed!

Two women sit at a wooden table with images of cups on them. Behind them is a white board with red and green writing. One woman has short dark hair tied back into a ponytail and glasses, and the other has blonde hair also tied into a ponytail and glasses. Both wear gray-colored clothing. — Olalla Prado-Nóvoa (left) and Kristen R. Howard work through the dietary records at the Human Integrative Physiology Lab. Photo courtesy of Kristen R. Howard.

This story was written in the spring of 2023 by GRAD 5144 (Communicating Science) student Kristen R. Howard and her colleague and post-doctoral fellow Olalla Prado-Nóvoa.

The health benefits of being active are widely known. You’ll keep yourself fit, build strong muscles, and reduce cholesterol levels, and the “feel-good” chemicals dopamine, serotonin, and endorphins will improve your well-being.

But many questions about physical activity are still unresolved: Can I have an extra pizza slice because I am training for a marathon? If I run more than 30 miles per week, can I have as much cake as I want? Am I burning twice the calories because I am twice as active as my friends and colleagues?

As disappointing as it may be, if you think “I go to the gym so I can eat what I want,” you may be wrong. Finding out for sure was the motivation of the Human Integrative Physiology Lab team, led by Dr. Kevin Davy in the Department of Human Nutrition, Foods, and Exercise at Virginia Tech, when the research project “The energy expenditure across the spectrum of physical activity” was designed.

This project put together two researchers, Kristen R. Howard and Olalla Prado-Nóvoa. Coming from very different disciplines, they share their main research topic: how a better understanding of our metabolism and exercise adaptations can help us promote health. Howard, a nurse practitioner and Ph.D. student in the VT Translational Obesity Research Interdisciplinary Program, is motivated by studying humans who are alive today to help them deal with their health issues. Prado-Nóvoa, an anthropologist and a postdoctoral researcher in Virginia Tech’s Presidential Postdoctoral Fellows program, is looking for the evolutionary roots of the problems caused by our current lifestyle.

You might say that Howard lives in the present while Prado-Nóvoa lives in the past, but together they are testing the latest hypotheses suggesting that the calories we burn each day have a limit. This limit may be maintained through a variety of mechanisms, and they are interested in learning more about these mechanisms. The calorie-burning limit may be imposed because our bodies change and adapt to exercise demands to reduce the cost of other biological processes, such as our immune systems or resting metabolism.

In a laboratory environment, a woman with tied-back blonde hair and glasses, wearing blue medical gloves, stands behind a computer. To her right, a young Black woman runs on a treadmill and wears a breathing apparatus. — Human Integrative Physiology Lab team during a maximum aerobic capacity test. Photo courtesy of MacKenzie Tyree Cassady.

Thus, even if you are participating in ultra-endurance races, more activity does not always necessarily mean more calories burned. These unconscious and/or physiological adaptations to exercise may not be helpful if we want to eat an extra hot dog after practice but were probably essential to keeping us alive during conditions of scarcity during human evolutionary history.

Is it possible that we have evolved to be unconsciously lazier? To want an extra piece of cake because we made a short run to catch the bus? Is there an evolutionary reason that makes getting up off the couch so difficult for us sometimes?

To answer some of these questions and more, the team needs participants to assess how many calories our bodies burn just to stay alive (resting metabolic rate), how much exercise we do (measured by accelerometry), how much we eat (measured through dietary records), and the total calories we expend every day. To get this last measurement, the lab is using the Doubly Labelled Water Technique, a procedure that is considered the most accurate, is completely non-invasive, and consists of having the participants drink a glass of water containing a certain amount of deuterium and oxygen 18 isotopes. These isotopes exist naturally in our bodies, and the amount contained in the glass of water is completely safe.

If you are a runner or ultra-runner and you want to get involved, you can contribute to the work by participating as a volunteer. Contact the research team at vtultrahipl@gmail.com, and the researchers will get you all the information about serving as a research subject.