Caffeine is a well-established ergogenic aid believed to increase strength and muscular endurance. An increase in strength suggests a centralized impact, or an “outflow” effect, on the central nervous system (CNS). An increase in muscular endurance suggests an impact of caffeine on peripheral factors such as the myoneural junction or others that locally impact muscular contractions. The present study was conducted to determine the predominant impact of caffeine, either on central or peripheral factors that govern muscular contraction, or both. Data concluded that (1.) muscular strength increased from control in both the caffeine and placebo trials, and (2.) there was no improvement in muscular endurance in the caffeine and placebo trial when compared to control; however, during the isokinetic endurance test, there was a modest increase in peak torque in the caffeine trial when compared to control. This study was conducted with approval from the Hanover College Human Subjects Institutional Review Board.