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Thousands of companies battle over the $20-billion U.S. dietary supplement industry every day, trying to turn profit by selling vitamins, minerals, botanicals, meal replacement supplements and various sports nutrition products. With all the money exchanging hands, from research and development to overly hyped-up advertising, it’s often hard for the average bodybuilder to separate fact from fiction. Looking at clinical evidence, conclusions based on scientific observation, as well as anecdotal reports from trained athletes, two over-the-counter supplements consistently come ahead of all others: creatine and caffeine.

In March 2009, Creatine and caffeine were announced as “ergogenics that work as claimed” by the American Dietetic Association, Dieticians of Canada and the American College of Sports Medicine. The professional sports society’s statement was made in an official position stand on nutrition and athletic performance. Creatine is an effective supplement for fueling repeated short bursts of high-intensity activity. Caffeine is an effective CNS stimulant that decreases an athlete’s perception of effort; furthermore, it helps mobilize free fatty acids and spare muscle glycogen. Creatine-containing supplements are not prohibited by the International Olympic Committee and caffeine ingestion is only banned over a certain limit. In general, their use in sports is generally left to each athlete’s discretion.

Creatine

Creatine is currently the most widely used performance-enhancing substance by bodybuilders and powerlifters. Numerous ergogenic effects have been documented in clinical studies over the last 15 years. It is effective at enhancing anaerobic energy systems for intense resistance exercise. People who train for strength, power and speed use intramuscular stores of adenosine triphosphate and phosphocreatine as the primary energy substrates. Creatine is an important source of chemical energy for muscle contraction because it can create phosphocreatine or donate phosphate to adenosine diphosphate to form adenosine triphosphate, catalyzed by the enzyme creatine kinase.

While research using previously untrained subjects isn’t nearly as conclusive, numerous studies have reported creatine’s positive influence on strength performance and body composition in already trained individuals. To see the most benefit from creatine supplements, previous resistance training efforts should have re-enforced accurate motor control to train against resistance with extreme intensity. Additionally, individuals should already have a considerable amount of muscle mass, dense tissue primed to take advantage of any increase in intramuscular energy pools. Women tend to respond less to creatine supplementation than men, which is likely due to less lean body mass. Reasonably muscular men are likely to increase one to two kilograms of body mass, or more, with only short term use. This quick volumizing affect is a result of an increase in intramuscular creatine and hydration levels. Combined with progressive resistance training, continued use will assist in increasing muscle cross-sectional area.

In May 2009, the Journal of Strength and Conditioning Research published a study reviewing two and five days of creatine loading on muscular strength and anaerobic power in trained athletes. Seventeen men, each with a history of resistance training, ingested either creatine or a placebo, a substance that was “similar in appearance and taste” to creatine. A traditional 20-gram loading protocol was administered: four five-gram doses per day, over five days. Anaerobic power and strength performance measures were conducted in the morning before the supplementation began and then on the third and sixth days, to establish the effect of two and five days of creatine loading, respectively. The study found that a five-day creatine loading regime quickly and significantly improved average anaerobic power during resistance training, as compared to training alone. Creatine uptake in the body improved after two days but the greatest ergogenic effect occurred after five.

Creatine use offers no prevalent performance advantage for endurance exercise that primarily taps aerobic energy pathways. Aerobic metabolism uses oxygen to generate cellular energy where oxidative phosphorylation produces most of the muscle’s adenosine triphosphate. To sustain endurance through repeated exercise (running, cycling), the aerobic process is much more effective than anaerobic metabolism. Athletes engaged in mixed events, like rowing and swimming, might benefit from creatine use.

A typical diet generally serves up around one gram of creatine each day. A diet high in protein-rich foods yields much more – 500 grams of fresh, uncooked steak contains around two grams of creatine. Creatine can be created endogenously, in the liver, kidneys and pancreases from glycine, arginine and methionine. Although creatine is considered safe in healthy adults, the most common adverse effects include weight gain (fluid retention), cramping, nausea and diarrhea.

Caffeine

Caffeine’s action as a central nervous system stimulant receives the most attention but studies on athletes have also shown a decreased perception of effort during exercise. Also, it increases the use of fats for fuel which, in turn, limits carbohydrate consumption, thus delaying muscle glycogen depletion. At nine kilocalories of energy per gram, fats are a much more potent energy source than carbohydrate or protein, both yielding only four kilocalories.

In September 2007, researchers from the Department of Kinesiology at California State University, Northridge, published a review of the physiological effect of caffeine ingestion on one-repetition maximum muscular strength. Few studies have documented caffeine’s ability to boost strength performance. One hour prior to exercise, they administered either a placebo or six milligrams of caffeine per kilogram of body weight to 22 resistance-trained men. Everyone refrained from caffeine intake for two days prior to each performance-based study. The researchers did not note a significant change in bench press or leg press performance. However, they did note an 11- to 12-percent increase in endurance with caffeine supplementation. Greater endurance results in a better peak power output when training with short or no rest intervals, or when training large muscle groups with heavy loads.

In April 2008 research published in the International Journal of Sport Nutrition and Exercise Metabolism reported caffeine’s potential to increase testosterone secretion in response to resistance exercise. The anabolic actions of testosterone can help promote quick recovery by encouraging an environment that favors muscle growth. Large doses of caffeine can counteract this benefit by increasing cortisol secretion, which causes a catabolic environment from a resultant decline in the testosterone-to-cortisol ratio. Caffeine’s desirable effect on testosterone levels seems to be best acquired at doses around 400 to 600 milligrams.

Contrary to popular belief, recent reports show that caffeine in moderation does not cause dehydration or electrolyte imbalance. Nonetheless, when rapid rehydration is needed, caffeine-free beverages should be used. Caffeine in excess can be potentially dangerous. Popping pills, slamming caffeinated beverages and snacking on caffeine-laced sports bars can lead to unhealthy amounts. Adverse effects include dependency, anxiety, jitteriness, rapid heartbeat, gastrointestinal distress and insomnia.

Creatine and caffeine, together?

Since caffeine and creatine independently increase performance, the next logical step is to combine them. The concept of creatine-caffeine synergy was quickly crushed by a 1996 study published in the Journal of Applied Physiology, during a period when creatine was butting heads with plenty of too-good-to-be-true skepticism. Belgium researchers concluded that caffeine counteracts the ergogenic action of muscle creatine loading – suggesting that creatine’s effects are “completely eliminated by caffeine intake.” They put another nail in the combination’s coffin in a follow-up study. Using the same protocol, they concluded that caffeine inhibits phosphocreatine resythesis during recovery.

Both studies against creatine-caffeine use hold little credibility with many strength coaches, since their crossover design alternated brief three-week washout periods between creatine and placebo treatments. Reliable results were easily disrupted since creatine loading will continue to affect an athlete’s performance for a month or more after discontinuation, especially when elevated creatine levels are being maintained with a diet containing plenty of creatine-rich foods. Furthermore, both studies against concurrent creatine and caffeine use showed that creatine loading into the muscle was not obstructed by caffeine ingestion.

The study design concern was voiced in a 1998 American College of Nutrition review of creatine supplementation and exercise performance; wherein researchers called for more research into creatine’s use in sports and warned: “… an appropriate washout period, at least a month or more, should be used in studies with crossover designs.”

Gym talk often suggests that caffeine impairs creatine uptake as a result of aggravated dehydration. As noted in several studies in recent years, caffeine is not the potent diuretic once claimed.

To get the biggest bang for the buck, strategically use each supplement by aligning them with immediate training goals. Use creatine during strength-training, muscle-building cycles, while staying well hydrated and avoiding chronic caffeine use. Caffeine is best employed when training goals focus on fat-loss, muscle preservation and improving endurance capacity.

Law, Yu Li Lydia 1; Ong, Wee Sian 2; GillianYap, Tsien Lin 3; Lim, Su Ching Joselin 1; Chia, Ee Von. Effects of two and five days of creatine loading on muscular strength and anaerobic power in trained athletes. Journal of Strength & Conditioning Research. 23(3):906-914, May 2009.

American Dietetic Association; Dietitians of Canada; American College of Sports Medicine, Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009 Mar;41(3):709-31.

Beaven, Hopkins, Hansen, Wood, Cronin, Lowe. Dose Effect of Caffeine on Testosterone and Cortisol Responses to Resistance Exercise, IJSNEM, Vol. 18, Iss. 2, April 2008.

Armstrong LE, Casa DJ, Maresh CM, Ganio MS. Caffeine, fluid-electrolyte balance, temperature regulation, and exercise-heat tolerance. Exerc Sport Sci Rev. 2007 Jul;35(3):135-40.Click here to read

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

Ziegenfuss et al. Performance benefits following a five day creatine loading procedure persist for at least four weeks. Abstract presented at ACSM 1998.

Vandenberghe K, Van Hecke P, Van Leemputte M, Vanstapel F, Hespel P. Inhibition of muscle phosphocreatine resynthesis by caffeine after creatine loading. Med Sci Sports Exerc 29: S249, 1997.

Vandenberghe K, Gills N, Van Leemputte M, et al. Caffeine counteracts the ergogenic action of muscle creatine loading. J Appl Physiol 1996;80:452-7.

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