Part 1

Abstract: Since the new year, many of us have made resolutions of heading to the gym and shedding some pounds and/or getting swole, breh. In order to make the most of our workouts, some of us spend way too much money invest in a potpourri of supplements, including protein shakes (whey, soy, egg, rice…), pre- and post-workout supplements (i.e., caffeine and… more protein), weight loss pills, and much more. After spending all of this money, one may wonder this: Is the investment worth it? Part one of this post reviews the mechanism by which one popular workout supplement known as creatine works. Part two will clear up some misconceptions regarding its use.

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I have been skeptical of using creatine for a number of reasons: (1) It is expensive, (2) Evaluation of its effectiveness has yielded equivocal findings (depending on your goal), and (3) In high school, I was indoctrinated with lies regarding its nature (e.g., “Creatine is an anabolic steroid”… Newsflash: It’s not). After conducting a short literature search, I ultimately decided against my previous position and am now supplementing my diet with creatine (and whey protein).

Warning (Subjective material): I think I’ve noticed a big difference.

Proposed Mechanism of Action

Every cell in our bodies relies on a chemical known as Adenosine Triphosphate (ATP) as an energy source. Without ATP, virtually every process in our bodies would grind to a halt. Simply put: No ATP <=> no energy => death. In the context of this post, ATP is important for muscle contraction (… And relaxation, but we won’t go into the nitty-gritty physiological specifics… As a further aside, since I can’t contain myself, I will mention that lack of ATP is responsible for rigor mortis; It’s not until the body begins to decay that it goes limp (lolz) again).

Did I lose you? No? Good.

Specifically, the power lies in the P of ATP. In general, ATP transfers one of its P’s over to a molecule that needs some energy. In doing so, ATP becomes ADP (Adenosine Diphosphate – it’s only got 2 P’s now).

While performing metabolically demanding activities (i.e., working out), the body must keep ATP levels at a sufficient level such that energy needs are met. This is where creatine (Cr) comes into play; Cr reacts with ATP to form phosphocreatine (PCr) and ADP. Thus, creatine acts as a stockpile of phosphate which can be used in the conversion of ADP back to ATP. This conversion is facilitated by a family of enzymes referred to as Creatine Kinases, which catalyze the following reaction:

Holy fuck, Le Châtlier strikes again!

Some of you may be familiar with Le Châtlier’s principle, which is summarized by Wikipedia as the following:

If a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established.

Consequently, when energy levels are high (high ATP), this pushes the equilibrium to the right and PCr begins to accumulate. But when ATP is consumed during high energy demands, equilibrium is pushed to the left. The larger the PCr stockpile, the longer metabolically demanding processes can continue.

By taking creatine supplements, the body has a much larger stockpile of energy which may be utilized during periods of high energy consumption; thus, creatine supplementation lets you push yourself a little more than you would be able to otherwise.

(Note: There are several other mechanisms by which creatine is hypothesized to increase performance; however, for the sake of brevity, I have not covered them here. Consult [1] for a highly detailed review of creatine)

References

[1] Bemben MG, Lamont HS. Creatine supplementation and exercise performance: recent findings. Sports Med. 2005;35(2):107-25. Review. PMID: 15707376