Which of the following performance enhancers contains large amounts of caffeine?

Energy drinks are known for their high caffeine content, which serves as a stimulant that can enhance physical performance and reduce fatigue during exercise. The caffeine found in these drinks can improve focus, increase energy levels, and potentially enhance athletic endurance. This makes energy drinks popular among athletes and fitness enthusiasts looking for a quick energy boost before workouts.

In contrast, protein shakes primarily serve to support muscle recovery and growth rather than providing immediate energy through stimulants like caffeine. Anabolic steroids involve hormones that promote muscle mass but do not contain caffeine. Creatine supplements are aimed at increasing strength and power output through cellular energy production, but again, they do not provide the stimulant effects associated with caffeine. Therefore, the choice highlighting energy drinks accurately reflects the performance enhancer that is characterized by its large caffeine content.