Mora-Rodriguez et al. (2012) completed a study on men who have already spent years weight training (avg time 7 years) and how caffeine influences morning workouts. The workouts included working up to a 1 rep max in bench press, squat and isometric grip. The subjects completed the workout in the AM on placebo, in the PM and then in the AM on caffeine. The study was blinded and the participants were unaware when they received placebo or caffeine.
It was found that ingesting caffeine in the AM improved strength performance 2.5%-7.0% depending on the lift checked. This would tend to suggest that strength and power athletes who must train in the AM would benefit from some caffeine intake. The study used 3mg/kg of bodyweight or approx. So a 185lb athlete would require around 250mg of caffeine pre-workout or about 3 cups of instant coffee. While we do not advocate this level of degree of use, the ergogenic effect of caffeine cannot be denied. Just for comparison, Beck et al’s 2006 study used resistance trained men and caffeine and found that while upper body max strength improved, lower body strength did not improve, nor did peak power or mean power on wingate tests.
This would tend to indicate that perhaps during a peaking cycle for upper body strength, caffeine could be incorporated but in general should not be relied upon. Always remember, desire, hard training and proper recovery are 90% of the game.