Figure 1: Chemical Structure of Creatine
Assuming you’re not a true vegan, foods such as meat, fish, and milk should be on your grocery list of creatine-providing sources. For example, 2.2 pounds (1 kg) of raw meat contains approximately 4 grams (g) of creatine. To put things into perspective, you’d have to eat approximately 9 raw Quarter Pounders from McDonald’s to derive just 4 grams of creatine; that’s friggin’ McQueasy.
Here’s the Proof!
While widespread use of creatine as a dietary supplement did not occur until the early 1990’s, elite athletes have utilized creatine as an ergogenic aid since the 1960’s. Since the marketing of creatine supplements in 1992, there have been anecdotal reports and concerns that creatine supplementation may cause muscle cramping, muscle strains, dehydration, suppression of creatine synthesis, and a multitude of undetermined negative side-effects. To date, the only documented side effect reported in the scientific community has been weight gain [1,2,3,4]. Imagine that. You gain weight!
Recently, extensive research has been conducted to investigate a number of health/medical concerns. This research has shown no negative side effects in the areas of endogenous creatine synthesis [5-6], renal and liver function, [7-16] muscle and liver enzyme efflux, [7,9,10] blood volume [17,18-20] and electrolyte status, [10,21,22] blood pressure,  or general markers of medical safety. [2,7,9,18,20,23,24,25]
Real World Application
Considering all the safety studies that appear in the literature to date, one study deserves applause because of its combined laboratory and practical value within the scientific community. In this classic safety study, scientists  examined 98 Division IA college football players who did or did not ingest creatine over a twenty-one month time period. These athletes ingested 15.75 grams of creatine during a loading phase followed by 5 grams a day thereafter during the maintenance phase while participating in intense training and competition. Creatine users and non-users were evaluated on metabolic markers, muscle and liver enzymes, electrolytes, lipid profiles, hematological markers, lymphocytes and renal markers. The bottom line, this research revealed that short and long term creatine supplementation did not adversely affect markers of clinical health status between athletes who ingested creatine and athletes who did not during intense training and competition.
Creatine Supplementation: Athletic Injuries & Conditions
Anecdotal reports have also surfaced regarding creatine supplementation during intense training in hot/humid environments. Guess what? It’s bullshit! These reports suggest that creatine may predispose athletes to increase incidence of muscle cramping, dehydration, and or musculoskeletal injuries such as muscle strains. [26-28] Baloney, I say . Here’s the proof!
Ninety-eight athletes participating in the 1998-2000 football seasons who did or did not ingest creatine following workouts and practices (15.75 g of creatine for 5-d followed by ingesting an average of 5 g/d thereafter administered in 5-10 g doses) were evaluated. These athletes practiced or played in environmental conditions ranging from 8 to 40 °C (mean 24.7±5 °C) and 19 to 98% relative humidity (49.3±17%). Shit. That’s hotter than the Texas sun; oh yeah right, it was in Texas where they did this study.
It was found that creatine users had fewer incidence of cramping (37 incidence by creatine users to 96 incidence by non-users, 39%), heat/dehydration (8 to 28, 36%), muscle tightness (18 to 42, 43%), muscle pulls/strains (25 to 51, 49%), non-contact joint injuries (44 to 32, 33%), contact injuries (39 to 104, 44%), illness (12 to 27, 44%), number of missed practices due to injury (19 to 41, 46%), players lost for the season (3 to 8, 38%), and total injuries/missed practices (205 to 529, 39%). It was concluded that creatine supplementation does not increase the incidence of injury or cramping in Division IA college football players. Mmm…so much for the cramping.
In a closely related study , investigators examined the effects of creatine supplementation on cramping and injury occurrence in 38 Division IA football players over a single competitive season. The findings in this study revealed that the incidence of cramping, dehydration, muscle tightness, muscle strains, and total injuries among creatine users were significantly less than the non-users. Did you see that? Less, not more. Less…mmm…read on.
Finally, researchers examined the effects of creatine supplementation on cramping and injury of 21 Division I collegiate baseball players during six months of training and/or competition.  These athletes ingested 15 to 25g/d of creatine for 5-d followed by 5 g/d of creatine after practices or games. Environmental conditions for these athletes during training and competition ranged from 27 to 35 °C (mean 30.4±0.6 °C) and 59 to 91% relative humidity (77.1±2.53%). While no heat/dehydration events were reported for either group, the creatine-users had significantly fewer total injuries than the non-creatine users. Do you see a pattern?
Creatine Used In The Medical Community?
Due to the vast number of existing studies revolving around the ergogenic benefits of creatine supplementation, some professionals believe now is the time to investigate the potential therapeutic role that creatine ingestion may have in treating various medical conditions. Since a small percentage of creatine is stored in the heart, initial research has considered the effects of oral creatine and intravenous creatine phosphate on heart function in clinical heart patients [32,33] and populations with creatine deficiencies. [34-41] Because creatine supplementation has shown to be extremely effective in promoting muscle mass gains in healthy populations, investigators have evaluated the effects of creatine ingestion with select neuromuscular diseases such as Huntington’s disease [42,43], amyotrophic lateral sclerosis [44,45] and Duchannes Muscular Dystrophy. [46-48] Investigators have also considered the potential effects creatine may have with brain and spinal cord injured patients [49-51] as well as the reduction of atrophy due to immobilization. [52-54] Further, investigators have considered creatine’s therapeutic role as a method to reduce cholesterol [55,56] and homocysteine levels. [57,58]
Take Home Message
While additional research is always warranted, the existing data suggests that creatine supplementation is a safe and effective nutritional strategy to not only enhance exercise/athletic performance but aid in the treatment of various medical conditions. And for the boneheads who say that creatine causes cramps, renal problems, and your babies to be born with two heads, tell ‘em they’re nuts! The proof is in the science.
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