By Chad M. Kerksick, Ph.D.
What are the essential foundations for staggering growth and impressive strength? A challenging workout that signals your body to grow bigger and stronger and a diet that provides adequate calories with an appropriate balance of protein, carbs and fats. Assuming the foundation of your diet is in order, it might be time to take it to the next level. In the past five years, the subject of delivering nutrients before a workout has attracted significant attention, putting the spotlight on a number of ingredients considered to be highly effective in helping to sharpen focus, offset fatigue and promote the completion of a greater number of sets and repetitions while also facilitating recovery.
The Heat Behind the Hype
It’s one thing to talk about the individual impact of key ingredients in preworkout formulations, but the conversation changes immensely when you can also discuss results from studies that directly investigate currently available commercial formulations. Fortunately, several examples of well-controlled studies have been published in peer-reviewed journals that explore popular preworkout supplements, and most of them are highly favorable.
• Researchers at the College of New Jersey had eight resistance-trained college-age men complete a single workout consisting of four sets of no more than 10 repetitions using the squat and bench press. When subjects ingested a preworkout product containing a mixture of caffeine, creatine, beta-alanine and BCAAs, a significantly greater number of repetitions was completed in addition to increasing average and peak power outputs.
• A two-part study completed by authors at Florida State University required 24 college-aged men to supplement with a preworkout or a placebo for six weeks while completing a heavy resistance-training program. Testosterone levels increased in both groups, but significantly greater increases in lean mass, fat-free mass and peak anaerobic power were found in the group that consumed pre- and (not surprisingly) postworkout supplementation.
• University of Oklahoma researchers reported significant improvements in critical velocity, training volume and lean body mass in study participants who completed high-intensity interval running over a three-week period and supplemented with a preworkout containing a combination of whey protein, creatine, caffeine, cordyceps, citrulline and ginseng.
• Similarly, University of Tampa scientists reported that eight weeks of supplementing with a combination of BCAAs, creatine, beta-alanine, quercetin, nitrate sources, alanyl-glutamine and B vitamins while completing a whole-body heavy resistance-training program significantly improved strength, lean mass and muscle thickness.
• Lastly, a team of investigators supplemented study participants in a preworkout fashion with a combination of beta-alanine, BCAAs, nitrates, caffeine, choline and cinnamon extract, leading to conclusions that preworkout supplementation increased reaction time, muscular endurance, feelings of energy and reductions in feelings of fatigue.
While this type of research is invaluable, as it allows potential users to understand nutrient combinations that are actually available on supplement-store shelves, exploring the active ingredients that drive these formulations is also necessary. After all, if you happen to be allergic to pepperoni, that doesn’t mean you have to throw out the whole pizza.
Caffeine is a mainstay in nearly every preworkout supplement on the market, and for good reason. For at least three decades we’ve known that caffeine helps improve many aspects of exercise performance, promotes a greater tolerance for exercise stress and heightens energy levels. Recent studies using caffeine during resistance exercise demonstrate a positive ability for caffeine to enhance strength and assist the completion of a greater number of reps at a fixed amount of resistance. In addition, other studies using caffeine while resistance training have reported that mood state, perceived exertion and muscle discomfort were all improved to significantly greater levels when compared to a placebo. In short, caffeine works powerfully to heighten your awareness and focus, which improves your mental approach to training and acutely increases strength levels.
This amino acid continues to be met with rave reviews across many fields of study. Supplementation enhances internal stores of phosphocreatine by 30 to 40 percent, resulting in an improved ability to produce ATP, particularly during stressful exercise. The list of favorable responses to exercise performance typically consists of strength enhancement, increases in lean mass, improved body composition and a greater ability to complete sets and repetitions — resulting in improvements in training volume that can be performed during standardized workouts. Entire articles and books have been written on the positive benefits of creatine. Year after year, studies continue to support its use as a safe and efficacious dietary supplement. Claims of dehydration, increased muscle cramping, pulled muscles and organ damage have been investigated by several different groups, but none have found scientific evidence to support these assertions.
Beta-alanine is one of two amino acids (the other is histidine) required for the production of carnosine, a physiological buffer found in muscle tissue. Carnosine production hinges upon the availability of beta-alanine. As a result, supplementation has become popular with athletes. For example, a study completed by a team of investigators from the United Kingdom had 13 male participants perform sprint cycling over four-week and 10-week time periods. Results showed a 13 percent improvement in total work after four weeks and an additional 3.2 percent improvement over the next six weeks (16.2 percent overall). Finally, a study performed on college football players had them supplement with beta-alanine during preseason training camp and concluded that athletes who used beta-alanine experienced reduced feelings of fatigue and were able to complete higher training volumes.
Branched-Chain Amino Acids (BCAAs)
BCAAs — isoleucine, leucine and valine — are a unique category of amino acids. The human body uses 20 amino acids to build new tissue, and nine of them are essential to the diet. Studies have shown that getting the essential amino acids in adequate amounts is critical to building new muscle protein. Moreover, studies also show that when duration and intensity are prolonged, the rate at which the BCAAs are metabolized increases. A study performed in the U.K. and recently published in Medicine & Science in Sports & Exercise found that participants who ingested a BCAA formula experienced a significant reduction in the amount of soreness after completing a single intense bout of muscle-damaging exercise.
From another angle, one of the BCAAs, leucine, has captured attention for its seemingly unique role in stimulating processes that increase muscle protein. A study published in the American Journal of Clinical Nutrition reported that when leucine was added to a combination that already included carbs and protein, the rates of muscle protein synthesis were increased even further when compared to a group taking only carbs and protein or those taking just carbs.
While most preworkout formulations include caffeine, creatine, beta-alanine and BCAAs as foundational ingredients, several other ingredients are often included.
• Betaine, for example, is a chemical derivative of glycine that is a somewhat new and a very promising consideration for sports performance. In 2009, researchers at the College of New Jersey had college-age men supplement for 15 days with betaine or a placebo and found that betaine improved endurance while squatting. Similarly, another study reported a significant increase in completed repetitions while bench-pressing after 14 days of supplementing with betaine.
• Nitrates are another popular ingredient. Interestingly, beets have an exceptionally high content of nitrates, with many supplements now containing various beet extracts. Research within the past five years has documented an ability of nitrate supplementation to reduce oxygen cost during submaximal exercise. Nitrates are also important due to their ability to rapidly promote vasodilation, which is thought to improve circulation and in turn maximize delivery of important nutrients to your muscles.
• Many preworkout formulations have also included any number of ingredients that are thought to improve neurotransmitter synthesis and cognitive parameters such as enhanced focus and mental drive. Tyrosine, for example, is an amino acid closely linked to the production of various neurotransmitters found in the brain; some research (but not all) has indicated that tyrosine supplementation may improve exercise capacity. Additionally, agmatine, a decarboxylated form of arginine, has been shown (mostly in animal studies) to favorably impact behavioral and cognitive factors, while also being linked to neurotransmitter synthesis and enhanced nitric oxide production.
The popularity of preworkout supplements is at an all-time high, largely due to their documented ability to boost performance and help improve body composition. This research (plus other viable studies that support the efficacy of key ingredients such as caffeine, creatine, beta-alanine and BCAAs) makes preworkout products a key consideration for anyone seeking to maximize workout effectiveness.