A New Model For Introducing Undergraduate Students To Energy Budgets

Abstract

PURPOSE: Teaching the fundamental concepts of human bioenergetics and energy expenditure (EE) to students can be difficult because the units of measure (e.g., joules/hour, watts, calories, Calories, METS, etc.) are often abstract and intangible. Moreover, the calibration and proper use of respirometry equipment needed to make accurate metabolic measurements can be a college course in itself. We sought to address these issues by developing an easy-to-use, self-calibrating respirometry system that students with no previous experience in respirometry could use to measure their own energy expenditure (in terms of Cal/day) in real time and model their energy budgets. METHODS: The system was then given to a sophomore biology student and who was asked to make predictions about her EE during various activities (i.e., sitting, standing, reading, texting, cycling, and crunches) and then make actual measurements to test those predictions. The student used the device during the subsequent four weeks to examine her predictions. RESULTS: Data supported her hypothesis that the EE would not differ between measurement modalities; paired-tests of EE collected using a facemask (5-min.) vs. a whole-body respirometry tent (10-min) showed no significant differences while sitting (p=0.487), laying (df=18, p=0.370), or reading (p=0.160). Contrary to her hypothesis there were no differences in EE while resting at different body positions (laying vs. sitting; df=38, p=0.968), or seated while reading vs. texting (df=18; p=0.414). Her hypothesis that standing caused higher EE was higher (~15%) than sitting (df=18, p=0.033) was supported. The two forms of exercise she compared (crunches vs. cycling) revealed much larger (3.4-fold) differences in EE than she predicted (df=18, p<0.001). CONCLUSIONS: Our next step will be to develop student teaching modules so that students working in small groups can practice experimental design and hypothesis testing to learn more about modeling their own energy budgets.