If asked to name the most accepted and researched performance- enhancing substance in the world, most people would answer "Creatine." Despite the impressive list of publications supporting the use of Creatine, its support pales in comparison to another product that is automatically included in many product formulations and is consumed by more Americans than any other performance product.

What is this wonder substance? And if it's so widely known and has such power, why doesn't it immediately register? The product is caffeine. Caffeine has become so accepted and so familiar that it's not given its due respect. Consider the number of people who consume caffeine daily, most making it part of their morning ritual in the form of coffee, tea or soda.1,2 It has integrated itself into beverages and tablets and capsules in such a devious manner, that it's rarely acknowledged as being present.

Numerous studies have shown positive ergogenic effects with caffeine use and it's considered safe to use.2,3,4 The same sports organizations that routinely ban any substance with performance-enhancing benefits allow caffeine to be used at doses that are in excess of common levels of consumption. Despite being highly effective at improving the performance of athletes and soldiers, caffeine has been most widely used in the formulation of fat-loss products.

Impressive Fat Burner
Caffeine has an impressive resume as a fat burner, with many published studies documenting its effectiveness at dropping pounds and reducing body fat.5,6,7 These studies have shown caffeine to be capable of increasing the release of stored fat, as well as the rate at which calories are burned. The net results are statistically significant, but in the real world are not sufficient for the fat loss desires of overweight couch potatoes or competitive bodybuilders. Caffeine is able to increase the resting metabolic rate only slightly; noticeable fat loss would require many months of constant use.

The effects of caffeine are best realized when used with certain other drugs or supplements. This fact is the basis for the inclusion of caffeine in combination with many different compounds. The most popular combination (and the most effective) has been the ephedrine/caffeine mix. Other ingredients have been combined with varying degrees of success, including green tea extract, yohimbine, synephrine, etc.

Recently, a paper was published that demonstrated the true effectiveness of caffeine and reviewed the many pathways by which caffeine accomplishes fat loss.5 Acheson, et al, investigated the effect of caffeine on lipolysis (release of stored fat from fat cells), oxidative lipid disposal (burning fat calories), non-oxidative lipid turnover (breaking down fat that is not burned for energy and then reforming it as stored fat) and energy expenditure (the total number of calories burned).

Caffeine promotes fat loss at two major sites- fat cells and muscle cells. The action of caffeine at the fat cell appears to be predominantly supportive to the fat loss signal generated by neurotransmitters and drugs that stimulate beta(B)-adrenergic receptors.8,9 These receptors are stimulated by adrenalin (the hormone that causes a rapid heart rate during periods of excitement) and similar chemicals. The level of adrenalin-like drugs, hormones and neurotransmitters released at any point in time is called the "sympathetic tone." The sympathetic tone may rise quite high during a "fight-or-flight" response or it may be low during periods of rest or sleep. Regardless, beta-adrenergic receptors are constantly being stimulated to some degree to maintain blood pressure, Mental Focus, energy (glucose and fat) levels, etc. At rest and without the addition of caffeine, there is not much fat release or increase in calorie burning because of the negating effect of a competing class of adrenergic receptors called A2-adrenergic receptors. While B-receptors promote fat loss and increase calorie burning, the A2-receptors do the opposite.10 Dan Duchaine had recommended the use of yohimbine to block A2 receptors while using fat loss products.