Fitness: Can pills, powders and bars improve athletic performance?

It’s a rare athlete, whether recreational or elite, who doesn’t take some sort of dietary supplement. Whether it’s a couple tablespoons of protein or creatine powder in a smoothie or a hit of caffeine, the promise of improved performance or enhanced recovery is a powerful motivator for anyone who takes his or her workouts seriously.
Yet as popular as they are, there’s little proof that supplements live up to their billing. Most studies have been equivocal regarding their