The effects of acute caffeine intake on cycling efficiency and cycling performance

Students: Justin Hou, Shrena Desai, Melissa Radlinsky, Sheriene Arikat, Nathan Brokaw, Libby Sarto, Petri Alva, Beshoy Yousif

Faculty Mentor: Bulent Sokmen

Kinesiology

College of Science, Technology, and Business

The purpose of this study was to examine the effects of acute caffeine intake (3 mg⋅kg⁻¹) on cycling efficiency, blood lactate and glucose levels, electromyograph (EMG) responses, maximal voluntary isometric strength, and pain perception during time trials following 90 minutes of intermittent cycling in trained individuals. A double-blind, randomized, crossover design was used, consisting of two experimental trials—one with caffeine and one with a placebo—separated by at least one week. After consuming a standardized breakfast, participants completed a 90-minute intermittent cycling test on a stationary ergometer, alternating three minutes at 30% VO₂max with one minute at 100% VO₂max, followed by a time trial at 90% VO₂max. Maximal hand grip strength with EMG, heart rate, rating of perceived exertion (RPE), and blood glucose and lactate levels were measured at pre-exercise, 30, 60, and 90 minutes, as well as at the end of the time trial.