The Ultimate Guide To Creatine Supplementation Part 1

In all probability, creatine is the most scientifically significant sports supplement of the past three decades. Several well-controlled studies have demonstrated a wide variety of benefits, which I’ll examine here. Most people, however—including supplement manufacturers and marketers—fail to understand what creatine does at the cellular level. In their material, as a result, they make claims we know to be false.

Creatine is not something to be trifled with. What you have to realize is that altering your creatine levels affects your body at the most intimate and microscopic levels. This can cause changes in nearly every cell inside your body.

A word of warning before we begin: This article delves deeply into the science of creatine and what it does at the cellular level. You don’t need to know this information, but since so many crappy blogs and pseudo-experts provide such inaccurate information on the subject, my goal here is to greatly expand our communal understanding of creatine and its role in the body. In Part 2, I’ll go into its day-to-day advantages and optimal dosing strategies.

 

What is Creatine?

I’ve read and heard countless times that creatine is the active transport of ADP back into ATP. While vague, this concept is brilliantly simple. It’s the same statement I read in FLEX magazine thirty years ago, and it’s been preserved perfectly throughout the interwebs by bro-science gurus ever since. I’ll admit to having used this same explanation myself for the sake of avoiding further discussion simply because it’s so damned elegant—but what the hell does it even mean?

First, a bit of history. Creatine isn’t a recent discovery. We’ve known about it for over a hundred years[1], and we’ve even known, for the majority of those hundred years, that supplementing with extra creatine can be beneficial[2-4]. Old-school supplementation entailed eating meat. In modern times, we can just buy a canister of grainy-white powder, mix it with water, and chug to our heart’s content. Compared to what’s possible naturally, this lets us take our creatine in mega-doses.

ADP and ATP stand for adenosine di- and adenosine tri-phosphate, respectively. ATP is the energy currency of your cells, and ADP results from the breakdown of ATP, which releases a phosphate molecule and ADP. ADP is then recycled, a phosphate is reattached, and ATP is formed again. On the surface, it’s a simple process.

Each of your cells contains mitochondria, which are dedicated energy producers. Mitochondria convert fatty-acids, ketones, and glucose into ATP via the infamous tricarboxylic acid (TCA) cycle, which you likely know as either the Krebs cycle or the citric acid cycle.

At rest, mitochondria don’t actually emit ATP or absorb ADP—which can be recycled into ATP in mitochondria[5-8]. Instead, creatine interacts with an enzyme system called creatine kinase (CK) that’s located on the outer surface of mitochondria. It then picks up a phosphate molecule from ATP in the mitochondria—turning the ATP into ADP[9-13]. Once the creatine grabs a phosphate, it’s then called creatine phosphate.

Creatine phosphate then delivers the phosphate to the area of the cell that does work, where, once again, creatine kinase removes the phosphate from creatine phosphate and combines it with ADP at the source of work. This converts the ADP back into ATP. Essentially, creatine transports the energy produced by mitochondria directly to the working parts without invoking a long series of chemical steps. It’s elegant, amazing, and efficient.

At its most basic level, creatine is the material that keeps all of our cells supplied with energy through a very efficient mechanism, while keeping intracellular ADP levels extremely low.

 

Quick Energy

It’s important to keep intracellular ADP levels low, because as this concentration increases, cellular respiration decreases and can trigger the need for faster energy[14-17]. In other words, ADP buildup influences how soon the glycolytic cycle is turned on during intense bursts of work. By keeping ADP levels low and recycling ADP back into ATP at the site of work, you can produce peak power for a slightly longer period of time. This is the second major advantage of creatine within the cell.

 

When you try to produce a large amount of power in a very short timeframe—during an Olympic lift, high-intensity repetitions, or the acceleration portion of a sprint—your muscle cells (especially your myofibrils) need excess energy fast. This is where the first of three energy systems comes into play. 

Cells have three energy systems. One of these is aerobic, and the other two are anaerobic. Of the two anaerobic energy systems, most people know about the glycolytic system, where glucose is burned rapidly to produce ATP. The other, which actually kicks in before the glycolytic cycle, is the ATP-Creatine-Phosphate (ATP-CP) system[18-21]. When you ramp up power production quickly, your cells need ATP at a rate higher than free creatine can supply by grabbing a phosphate molecule and delivering it to the myofibril to get turned into ATP and then burned.

In contrast, when intense activity begins from rest, we already have a huge store of ATP and creatine phosphate. The cells burn through the ATP stores, and creatine phosphate recycles the resulting ADP into ATP rapidly, but CP becomes exhausted in the process. Within cells, ATP levels never fully deplete, even at fatigue. Creatine phosphate levels, however, can become almost totally exhausted[22-23].

 

A Bigger Battery

Think of the ATP-CP system as a battery. During rest, your cells build a surplus of CP and ATP as it reaches equilibrium. Then, when it’s go time, you can tap into this surplus for rapid, almost free energy, because burning up the CP continues to prevent the buildup of ADP—which can decrease energy production when levels get too high.

This is one of the reasons why creatine supplementation gives you a boost. Supplementing with creatine can increase CP levels by roughly 20 percent[24-26]. This gives you a bigger battery when you need to produce massive amounts of power in very short periods of time.

This, however, is only a minor component. This battery is fast acting, only lasting long enough for the glycolytic cycle to ramp up—which, in turn, only lasts long enough for the oxidative system to ramp up[27-28]. These three aren’t completely isolated—they all can contribute energy throughout exercise or work—but they each have a sweet spot where they produce the majority of the energy for the entire system.

Since ATP-CP acts on such a relatively short timeframe (5 seconds[29]), it’s critical for resistance-type training, sprinting, and HIIT. This can be seen through research: creatine supplementation does almost nothing to enhance endurance in performance[30-34], but even relatively short exposure to supplementation can increase sprint and power performance[35-43].

This is one of the rare occasions when I’ll say that it’s possible that supplementation beats training. Through various regulatory mechanisms—and from vast amounts of data on athletes, coupled with mathematical models—it does not seem possible to train the ATP-CP system directly. It’s always tied with the peak output and timing of the glycolytic cycle[44-46]. Whatever the peak output is at which you train your lactic acid threshold, the ATP-CP system simply adjusts to reach the same exact peak, only in a shorter amount of time. In other words, the ATP-CP system only acts to bridge the first five seconds of high-output performance, in order to allow your glycolytic energy system to ramp up. Training may not be able to do anything to specifically alter the ATP-CP system in isolation.

Supplementation, however, seems to have the ability to do this.

 

Conclusion

If you didn’t know exactly what creatine did in the body, you should have a pretty firm grasp at this point. It is, quite simply, harkening back to the words of FLEX from 30 years ago regarding the active transport of ADP back into ATP. FLEX, at the time, just left out all the details—and bro-science has been happy to pass this explanation along without trying to understand what that statement actually means.

In next week’s installment, instead of dealing with the technicalities of creatine as an energy substrate, I’ll explain how creatine can make you bigger, stronger, smarter and even help you live longer.

The Ultimate Guide To Creatine Supplementation Part 2

The Ultimate Guide To Creatine Supplementation Part 3

 

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