CAFFEINE

Taking caffeine will give you a quick energy buzz before workouts, and it can also boost muscle strength. But research shows that caffeine, even in doses under 100 milligrams, also enhances attention span, concentration, memory and overall cognition.

L-THEANINE

You may recognize this amino acid as the component in tea that enhances relaxation. Many guys supplement with theanine to chill at night. But taking theanine any time of the day can boost brain function. Research published in a 2010 issue of the journal Appetite found that when caffeinated-tea drinkers took theanine, they performed significantly better on cognitive tests than when taking a placebo.

TAKE IT LIKE THIS

Take 100-200 mg of caffeine and 100-200 mg of L-theanine any time you need a brain boost, such as during work, when studying or before the gym to focus better when you train.