Bioenergetics and Environmental Stress Suite

The state-of-the-art and nationally unique Bioenergetics and Environmental Stress Suite inside the IU School of Public Health-Bloomington has three primary components that help address important translational research questions.

(1) Whole-Body Room Calorimeter

Our 12’ x 11’ enclosed calorimeter is the only system in the world to simultaneously measure energy expenditure and simulate altitude (~7,000 feet) by reducing the fraction of inspired oxygen. This enables researchers to mimic different environments and continuously measure human energy over extended periods (e.g., 24–72 hours), providing valuable real-time data across varying activities including rest, sleep, and light exercise. whole body room

How does it work and what makes it unique?
Indirect calorimetry is a technique through which measurements of respiratory gas exchange are used to quantify energy expenditure and estimate substrate oxidation, specifically lipids and carbohydrates.

With “fresh air” always supplied to the room, specialized sensors and sophisticated software can detect subtle changes in inspired and expired gases. Assuming that nitrogen is a constant in both inspired and expired air, sampling of gases within the enclosed room permits determination of oxygen uptake and carbon dioxide production.

Why is this valuable?
Room calorimetry represents an essential tool in our collective effort to understand the attendant consequences of obesity and cardiometabolic disease in humans. During prolonged stays in the room calorimeter, researchers can obtain an abundance of information that may prove impractical in other settings. Dietary manipulations to achieve energy balance, collection of various biologics (e.g., blood, urine, fecal samples), and assessment of sleep behavior are all readily feasible within our room calorimeter. Other important capabilities include manipulation of circadian rhythms and exercise. Bluetooth^®-equipped wearables can be used to remotely measure heart rate, physical activity, body temperature, blood pressure, and glucose.

(2) Flex: Calorimeter

This smaller (5’ x 8’) room calorimeter, most suitable during short-term observations (< 3 hours), provides unmatched precision in measuring energy expenditure during rest and even low-intensity, steady-state exercise.

The Bioenergetics and Environmental Stress Suite

The Bioenergetics and Environmental Stress Suite is the only facility of its kind in the United States, with complementary equipment providing for advancement of the translation of both clinical and human performance research in obesity, nutrition, and environmental physiology.

(3) Environmental Chamber

This 10' x 20' structure generates extremes in temperature, humidity, and oxygen content (simulated altitude).

How does it work?
Researchers can immediately change the conditions in the chamber, then observe the bodily response of participants.

Why is this valuable?
Laboratory-based measurements of responses to different environments provide accuracy and control that researchers cannot attain in the field. When the chamber is adjusted to replicate—for example—the conditions of an overnight stay on a mountain in Afghanistan, scientists can better understand human stress responses and make informed recommendations about both rest and exercise.

School of Public Health

Bioenergetics and Environmental Stress Suite