Ever since the ancient Chinese brewed the first cup of tea and Ethiopian herders noticed their goats jumping about after munching coffee beans, we’ve been hooked on caffeine. Each day, nine out of 10 Americans ingest some form of caffeine. Two-thirds comes from the morning coffee slam, and the rest is spread across sodas, tea, energy drinks, supplements and chocolate. We may be hyped about caffeine, but caffeine doesn’t deserve its hype as an addictive, dehydrating and dangerous drug. Far from it.

Used the right way, caffeine can provide a healthy stimulating effect for both brawn and brain.

Before & After

Mounting evidence shows that preworkout caffeine can increase endurance, which means more reps, more sets and longer sessions, which translates into bigger muscles. “Next to creatine, caffeine is probably the most effective performance-enhancer,” says Jose Antonio, PhD, CEO of the International Society of Sports Nutrition. Caffeine doesn’t directly affect muscles; instead, it influences the central nervous system [CNS] to increase your pain threshold, so it’s easier to push through those final reps, extra sets and last treadmill interval.

Research also confirms that caffeine can immediately increase muscle strength. Scientists from the University of Nebraska-Lincoln reported that weight-trained men who took a caffeine supplement one hour preworkout increased the number of reps they could complete on the bench press using 80% of their one-rep maxes.

Follow-up Study

In a follow-up study, the same lab reported that weight-trained subjects who took one dose of caffeine preworkout increased their max bench-press weights by about 5 pounds. A 2008 study by Indian researchers also found that when subjects consumed 2, 4 or 6 mg of caffeine an hour before training, their muscle strength and endurance increased with larger doses. This CNS effect also increases lipolysis, the breakdown of fat. This becomes an additional workout fuel source and triggers a thermogenic response to raise body temperature and promote calorie-burning. “So in effect, caffeine increases your fat-burning ability while it improves your workout performance,” Antonio points out. If you want to jump-start muscle refueling, make sure to add caffeine to your postworkout meal. Australian scientists found that endurance cyclists who ingested a beverage of carbohydrates and caffeine equal to 8 mg per kilogram of bodyweight about 5-6 cups of coffee had 66% higher glycogen levels four hours after exercise compared to those who drank a carb-only beverage. Caffeine increases glucose uptake from the blood into the muscles, and faster glycogen recovery means shorter recovery time and more energy for your next workout.

Caffeine is also believed to enhance the activity of several signaling enzymes, including protein kinase and protein kinase B, both of which enhance muscle glucose uptake. Higher glycogen levels also increase muscle size, since glycogen pulls water into muscle cells.

Works For Everyone

Another advantage of caffeine is it works the same whether you’re a caffeine junkie or teetotaler. Research published in the International Journal of Sport Nutrition & Exercise Metabolism in 2009 compared pain tolerance of 25 college-age men who were split into two groups: high caffeine users (400 mg per day, or 3-4 cups of coffee) and low consumers (100 mg or less). Subjects took 5 mg of caffeine per kilogram of bodyweight (2-3 8-ounce cups of coffee) and cycled for 30 minutes at a nearly 80% [VO.sub.2] max.

Brain Booster

Caffeine can pump up your gray matter, too and you don’t need as much. Scientists at the Innsbruck Medical University (Austria) discovered that just 100 mg of caffeine (1 cup of coffee) increases activity in the part of the frontal lobe that influences short-term memory and the anterior cingulum, the part of the brain that controls attention. Why does caffeine give you that slap-in-the-face brain boost? Basically, it’s a case of mistaken identity, Antonio says. Caffeine binds to adenosine receptors in the brain, which when adenosine is involved makes you tired but with caffeine speeds up brain-cell activity.