The use of primary research in the classroom enhances the critical thinking abilities of students. The present article describes a strategy for using the American Physiological Society classic paper “Enzyme activity and fiber composition in skeletal muscle of untrained and trained men” by Dr. Philip D. Gollnick and colleagues to enhance the students’ ability to understand research, increase their knowledge of the adaptations to exercise, and learn computer skills in data analysis and presentation. By having students read, study, prepare graphs, and discuss the data from a classic paper, they gain an improved understanding of the factors that influence aerobic exercise ability. This study is especially useful for illuminating the exercise-specific differences in bioenergetic enzymes, muscle fiber type, and fitness characteristics that exist between untrained and trained individuals.