Abstract
We used mixed methods to identify middle school students' conceptions and misconceptions of energy in the domain of health and fitness. We selected a total of 24 middle schools from six school districts in a Southeastern state of the U. S. through stratified sampling. Students were first given a standardized knowledge test to establish their knowledge level membership in the domain of health and fitness. A sample of 291 students was selected from the 24 schools for semi-structured interviews on their understanding of energy sources for physical activities and consequences of energy surplus. Analysis of the interview data identified a variety of misconceptions on energy by grade and knowledge levels. Different conceptual change theories were adopted to form four themes to explain the identified misconceptions. We discussed pedagogical implications that may help address the misconceptions in and beyond the domain of health and fitness.