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King Of Supps?

You couldn’t have seen it coming, this nutritional coup of epic proportions. You didn’t notice its slow, steady intrusion into the supplement hierarchy. For years, it has lurked in the shadows, relegated to some perfunctory part of your morning ritual or a peripheral ingredient in your preworkout mix. But now, with a still-growing, Alexandria-size library of research on this compound, caffeine is poised to become the king of all supplements — a product on every athlete’s shopping list, regardless of goal.

“I would place it right up there with whey protein, creatine and branched-chain amino acids,” says Jim Stoppani, Ph.D., author of Encyclopedia of Muscle and Strength (Human Kinetics, 2006). “It is one of the most studied supplements for sports performance, and there is a ton of research supporting its benefits for athletes.”


You won’t get marked down if you can’t remember caffeine’s scientific name — 1,3,7-trimethylxanthine — but it would be good for you to familiarize yourself with the ways caffeine affects your brain and body.

“The most widely known effects of caffeine, including the boost you get in energy and alertness, are due to the fact that it binds to adenosine receptors,” Stoppani says. “Adenosine is a breakdown chemical that is produced in the body, and when it binds to its receptors in the brain, it signals fatigue, making you tired and sluggish and slowing down nerve activity, which makes your brain more dull. By binding to adenosine receptors, caffeine prevents this fatigue signal and keeps you more alert and mentally focused.”

That alone is reason enough to keep knocking back your Starbucks in the morning. It’s important to consider, however, that most research on caffeine has been done using the stuff in supplemental form and that your morning mocha is likely laden with other not-so-physique-friendly ingredients.


Most people know that caffeine can get the morning off to a strong start or that it can push you through an afternoon crash. What you may not know is that caffeine has some serious showcase benefits for those looking to boost performance in the gym.

>> Fat Loss. “In fat cells, when adenosine binds to its receptors there, it inhibits lipolysis, or the release of fat from the fat cells,” Stoppani says. “So one of the main ways that caffeine works as a fat burner is by binding to adenosine receptors on fat cells to keep fat being released from fat cells, where it then can travel to other tissues and be burned away as fuel. It also increases your metabolic rate, or the number of calories your body burns each day, by about 15 percent.” Korean scientists from the Institute of Elderly Health in Seoul (South Korea) discovered when they gave caffeine to rats and humans and made them exercise to exhaustion, the amount of fat in the blood increased, as did endurance. “During exercise, the body begins to feel fatigued when muscle glycogen is burned and its levels drop,” Stoppani says. “Since the body will burn any free-floating fat in the bloodstream before tapping into glycogen stores, more fat being available to burn first equates to more time to exercise before fatigue sets in.”

>> Reduced Pain. Sometimes, the only thing separating a good set from a great one is your pain threshold. A study published in a 2003 issue of TheJournal of Pain found that subjects who took a large dose of caffeine an hour before doing 30 minutes of moderate-intensity cycling reported feeling significantly less muscle pain. “The implication of this study is that if you’re not hurting, you’ll be able to work out harder for longer,” Stoppani says. This reduced perception in pain, combined with caffeine’s effects on the nervous system, may lead to more reps and, eventually, greater growth.

>> Greater Strength and Size. Creatine’s effects on strength gain in athletes is well-documented, but researchers have never been able to lay claim to an instant, quantifiable boost in strength from taking it. However, one study found that 200 milligrams of caffeine an hour before workouts increased one-rep-max strength on the bench press by an average of 5 pounds, likely by increasing the firing rate of the nerves going to muscles, which can lead to stronger muscle contractions. The same group of scientists also found that trained subjects could do more reps with the same weight (80 percent of their 1RM) at that dosage. Caffeine, Stoppani says, may also act directly on muscles by triggering an increase in the release of calcium into the muscle. Calcium is needed for muscle contractions, so more calcium may lead to stronger muscle contraction and in turn greater force production by the muscle. The take-away? Greater acute strength and more reps during your workout will allow you to lay the groundwork for larger muscles.

>> Enhanced Blood Flow. Gym rats love their arginine for its ability to increase nitric-oxide production. But new research is showing that caffeine is also encroaching on arginine’s territory by providing many of the same benefits. “Although previous research suggests that caffeine constricts blood vessels, newer research in TheAmerican Journal of Cardiology showed that caffeine increased blood flow to forearm muscles by increasing NO levels,” Stoppani says. “Better blood flow means delivery of more nutrients like amino acids and glucose to muscles, as well as more oxygen, for better energy production during exercise.”


It’s clear that the use of caffeine can and should go well beyond your coffee mug. The most common recommended dose of caffeine is 200 to 400 milligrams — taking more or less than this dose can reduce effectiveness — of caffeine anhydrous taken 30 to 60 minutes before exercise. But this can vary, depending on a number of factors, including goals and tolerance.

“If you are trying to get bigger and stronger, then your best bet is to take 200 to 400 milligrams before and possibly immediately after your workouts, only on workout days,” Stoppani says. “However, if you are trying to lose body fat, then you should take about 200 milligrams two to three times per day between meals, with one of those doses being 30 to 60 minutes before workouts.”

Unfortunately, you can become desensitized to caffeine through continued use, and when you do, you can say goodbye to all its physique-friendly fallout. To avoid this, Stoppani suggests a few strategies.

One is to only use it before and possibly after workouts,” he says. “That means you do not take it on rest days or at other times of the day. This will help you to keep getting the maximum benefits from caffeine around workouts. However, if you also want to take caffeine for its fat-burning effects and/or cognitive benefits, then you do need to use it several times a day every day. In that case, your body will likely desensitize, and you will need to cycle off to regain the benefits. I would suggest cycling off every eight weeks for one to two weeks.”


Despite the overwhelming evidence of caffeine’s effectiveness, there is still a body of nutritionists that aim to demonize this compound, citing shaky research linking it to heart or kidney issues.

“Unfortunately, many people, especially ill-informed trainers and dietitians, warn against drinking caffeinated beverages or taking caffeine because it is a diuretic,” Jim Stoppani, Ph.D., says. “Yes, caffeine does act on the kidneys to increase urine volume, which is why it’s considered a diuretic, but the effect is very mild and certainly won’t affect your health or your workouts.”

Find more of Dr. Jim Stoppani’s advice on supplements, nutrition and training at