Everyone has heard of creatine. It was popularized by Mark McGuire (go Houston!) and credited for his enormous muscle and strength gains. Unfortunately, well, we all know what he eventually came out to be using...
Before I get into my diatribe about creatine use for athletic and strength gains, I want to emphasize that no amount of supplementation is going to overcome a bad diet. You don't have to be a bastion of Paleo perfection, but if you subside on Big Macs, clean that up first.
Creatine helps with workouts by providing a quick source for energy replenishment. The use of creatine will be most evident during workouts that involve short bursts of energy, as seen in anaerobic training and bodybuilding. They will also be more evident if your workouts tend to go longer than an hour.
2) Intracellular Action
Creatine is stored in the cell's cytoplasm as creatine phosphate. During anaerobic work and the initial phase of any exercise, ATP (adenosine triphosphate) is used for energy through the removal of a phosphate to create ADP (adenosine diphosphate). ATP stores are used in about 5 seconds of work.
To resupply the cells with ATP quickly, the phosphate in creatine phosphate is transferred to ADP, which is now usable again as ATP. This process of ATP restoration is referred to as the phospholytic cycle, and is depleted in about 15 seconds, so it is only useful for short, powerful bursts of energy.
After the creatine phosphate and ATP are used, enzymes in the cell take the free standing phosphates and reattach them to the expended creatine and ADP molecules. This process takes about 5 mins to full completion, which is why you'll often see powerlifters and Olympic lifters take several minutes off between maximal lift attempts.
3) Typical Protocol for Use
By increasing the amount of creatine in your muscles, you can increase the amount of time you have to complete a power movement. Also, with more creatine in your system, since some is excreted with each round of phosphate metabolism, you can usually keep you work capacity up through longer workouts. We're not talking super human capabilities, but when you're a strength / power athlete, each extra rep gets you closer to your goal.
Most short term studies use 20 g a day for a week of creatine monohydrate and see significant results. Study of loading and excretion show that when supplemented with 20 g per day, maximum levels are reached in 5-7 days. This 20 g is spaced out through out the day, definitely with doses before and after a workout.
After the 5-7 days of loading, most people are well supplemented with 5 g or less. There are body weight charts out there, where you can calculated exactly how much you need based on lean body mass, but with pure creatine monohydrate being relatively cheap, I'd recommend just sticking with the 20 g for loading, and 5 g for maintenance.
It is also recommended that once cycles on and off. Supposedly, some can develop a resistance to creatine supplementation if it is used constantly. Most often recommended is 8 weeks on, including the loading phase, and then four weeks off. You shouldn't see a drop in strength during the off phase, only perhaps a small decrease in capacity. These aren't steroids, after all.
First, for those in weight class sports, be aware that most people see an increase in body weight when they are on creatine. It can cause water retention in the muscle cells simply through the osmotic gradient created by extra "stuff" in there.
Second, some people experience some gas and GI tract annoyances. Get a monohydrate that looks more like a fluffy white powder than course crystals for one. Secondly, if you experience this, try to divide up the doses to smaller doses throughout the day.
Third, You really need to take this with a high glycemic liquid. Grapefruit juice is often recommended. I don't like the taste of it, so I'll do half grapefruit and half orange juice. I've also heard half grapefruit and half grape juice works well, too. Insulin acts as a transport hormone to "push" the creatine into your cells. (Also, if you are border-line insulin resistant, you might find yourself to be a "non-responder" since insulin can't work on your muscles like it should.)
Good luck and happy lifting!