Ergogenic Aids — Competitive Edge or Hidden Danger?
Learn which supplements can safely boost endurance, enhance exercise recovery, and improve athletic performance—and which do not—to better counsel clients.
The pressure mounts as Joy Dubost, RD, PhD, CSSD, a master's-level figure skater, competes to win a national championship. To win first place, she must glide effortlessly across the ice and maintain great posture, speed, endurance, strength, and height to perform triple toe loops and double axels with precision.
Dubost trains for 90 minutes six days per week. One hour before each training session, she drinks 16 oz of caffeinated coffee. "That gives me about 100 mg of caffeine," she says.
To repair muscle and boost glycogen stores, she drinks 1% chocolate milk after a hard skate instead of whey protein. "Rather than whey protein isolate, I get the benefit of all the essential nutrients found in milk," she says.
As a dietitian who understands food science, Dubost clearly has an edge over her competition. But the majority of athletes don't have that advantage. Most rely on hearsay as the gold standard for discerning whether an ergogenic aid is safe and effective. In fact, they're often willing to try almost anything to produce that winning edge.
According to the International Society of Sports Nutrition, an ergogenic aid is any training or psychological technique, mechanical device, nutritional practice, or pharmacological agent that can help improve exercise performance capacity or enhance physical strength. These aids help prepare an individual to exercise, increase exercise efficiency, improve exercise recovery, and adapt to the rigors of intense training.
This article will evaluate the scientific evidence for and against some of the most common nutritional ergogenic aids that competitive athletes use.
"The strongest evidence for using caffeine as an ergogenic aid is in endurance athletes," says Jennifer McDaniel, MS, RD, LD, CSSD, a specialist in sports dietetics and spokesperson for the Academy of Nutrition and Dietetics. Runners, cyclists, and cross-country skiers have been the primary subjects in these studies.
Anding also refers to caffeine as a "first step enhancer." She says small amounts of caffeine before a 100- to 400-m race can help the athlete with that first step.
Caffeine has been proven safe when taken in recommended doses. "The most recent evidence suggests that benefits from caffeine can be achieved by taking in 2 to 3 mg of caffeine per kilogram of body weight," McDaniel says. This amounts to 100 mg of caffeine for a 110-lb athlete. "However, adverse effects such as rapid heart rate, dizziness, and feelings of hypoglycemia [eg, lightheadedness, jitteriness] have been observed when taken in larger quantities or for athletes who are caffeine sensitive," she adds.
According to Heather Mangieri, RD, MS, CSSD, owner of Nutrition CheckUp, a Pittsburgh-based nutrition practice specializing in sports nutrition, and a dietitian working with adolescent athletes, cautions that caffeine doesn't work the same for everyone. "Some athletes may find that it makes them jittery, anxious, or hyper. For others, caffeine can prompt bowel movements," she says.
Studies report caffeine also may elevate blood pressure and heart rate.3 "So the day of a big competition is no time for an athlete to learn how caffeine will affect them," Mangieri notes.
Bottom line: Caffeine is safe when taken in recommended doses and is an effective ergogenic aid to improve endurance and high-intensity activity lasting up to 20 minutes.
Although carnitine is safe at recommended doses, it's not effective as an ergogenic aid.
Chromium is an essential mineral that enhances insulin sensitivity. Supplemental chromium usually is in the form of chromium picolinate. Picolinate facilitates greater gastrointestinal absorption.
Chromium picolinate has been marketed as an ergogenic aid with the promise of building muscle and promoting weight loss. Studies suggest chromium may enhance insulin's actions. Since insulin promotes protein synthesis, chromium has been theorized to serve as an anabolic nutrient. "It's also thought to enhance athletic performance and increase energy and vigor," Mangieri says.
While chromium is considered safe in recommended doses, there's no reliable evidence that it will boost lean body mass or reduce body fat.
"There are some things that just flat out work," Anding says. "If you're working hard in the weight room, training really hard … just when you don't think you can do one more rep, creatine can help with that edge" to complete the repetition.
At recommended doses, creatine is a safe and effective ergogenic aid that can increase muscle growth, strength, and power.
More research is needed to determine an appropriate dose for humans. Moreover, the safety of CLA in humans hasn't been established, and conclusions about its effectiveness as a weight loss aid for humans is mixed.
Branched chain refers to the chemical structure of the essential amino acids leucine, isoleucine, and valine. Athletes use branched-chain amino acids (BCAAs) to improve strength, power, and endurance. BCAAs started receiving more attention as an ergogenic aid when researchers discovered that after three hours of exercise, BCAA levels in the blood dropped dramatically, and the enzyme keto acid dehydrogenase, which is responsible for the breakdown, increased.
Nevertheless, taking 5 to 20 g of supplemental BCAAs per day in divided doses seems to be safe.2 However, they're not proven effective for improving performance.
Androstenedione is a prohormone that the body can potentially convert to testosterone. Some data indicate that prohormones increase testosterone levels; however, there's scant evidence that prohormones boost muscle mass in young men with normal hormone levels.1 In fact, most studies indicate androstenedione is dangerous, and that it doesn't affect testosterone levels. Study findings show it may increase estrogen levels and reduce HDL cholesterol, and is associated with at least 25 other life-threatening side effects,2 such as "an increased risk of breast, pancreatic, and prostate cancer," Mangieri says. In addition, there are safety concerns that the potency and purity of androstenedione products vary significantly.
These safety issues prompted Congress in 2004 to pass the Anabolic Steroid Control Act, listing androstenedione as a controlled substance that can't be sold without a prescription. For this reason, most sports-governing bodies list androstenedione as a banned substance. Also, it's not deemed safe or effective as an ergogenic aid.
Known as DHEA, dehydroepiandrosterone is another popular prohormone among athletes that's often promoted as a fountain of youth.2 It's said to increase testosterone levels, resulting in increased muscle mass and metabolic rate.
At this time, DHEA supplementation isn't recommended for athletes.
It's important for RDs to understand that supplement use is widespread among athletes of all ages and at every level. Aspiring athletes as young as those in middle school are using supplements.2 Adolescents often feel pressure to obtain athletic scholarships and look to ergogenic aids as a way to realize their goals. That's problematic because RDs don't have evidence supporting the use of nutritional ergogenic aids in young athletes. "Most of the research we have on ergogenic aids is done on the adult population over the age of 18," Mangieri says.
Elite athletes know that competitions are won or lost by slim margins, and many feel an ergogenic aid may be the silver bullet they need to win. Other athletes feel pressured to use nutritional ergogenics to maintain a competitive advantage over their peers who are already using supplements.
If athletes ask about a specific ergogenic aid, RDs should provide as much unbiased information as possible. Dietitians should tell athletes what's known and unknown about the product based on current scientific evidence, including potential side effects and safety issues.
RDs should help athletes understand that nutritional ergogenics may contain banned substances, which could lead to disqualification in their sport even if they were unaware that the supplement was contaminated. Anding tells athletes that "you and you alone are responsible for what goes in your body," and because ergogenic aids are unregulated, they may contain banned substances not disclosed on the product label.
• Develop competency. RDs who desire to work with competitive athletes need continuing education to stay abreast of the constantly changing and challenging aspects of nutritional ergogenics. Sports nutrition is popular, and many new dietitians are entering the sports nutrition field.
• Know the science. "Athletes are more knowledgeable than the average consumer; they take it [supplementation] very seriously and believe it will give them a performance edge," Dubost says. RDs should look at the total evidence, not just one or two supplements. Knowing the science is extremely important because athletes will come in well versed.
Athletic careers have been sidelined as a result of supplementation with products that are on the National Commission for Certifying Agency's banned substance list. Mangieri believes discussing this list is a great way to broach the subject of ergogenic aids.
• Address immune function. "We forget that athletes are immune compromised because of the stress of training. They need education on the proper diet and supplementation to support good immune function," says Dubost, whose biggest fear is not feeling well on the day of her skating competition. To ensure she maintains her competitive edge, she includes an immune supplement in her daily routine.
Asking the following questions and using these resources can serve as a guide to help nutrition professionals evaluate ergogenic aids and provide accurate information to clients.
• Check the FDA's website (www.fda.gov) for drug recalls, withdrawals, and safety alerts, and follow the FDA on Twitter @FDArecalls for timely information.
• Visit the Public Health and Safety Company website (www.nsf.org) for a list of substances that have been certified or banned in sports.
• Search reputable free databases such as PubMed (www.ncbi.nim.nih.gov/PubMed).
• Search member-only databases such as the Academy of Nutrition and Dietetics' Evidence Analysis Library (www.adaevidencelibrary.com), the Natural Medicine Comprehensive Database (www.naturaldatabase.com), and EBSCO (www.ebscohost.com).
• Read review articles about a specific supplement.
• Search websites with evidence-based supplement information, such as SupplementWatch.com.
Is the Supplement Free From Contamination?
1. Kreider RB, Wilborn CE, Taylor L, et al. ISSN exercise & sport nutrition review: research & recommendations. J Int Soc Sports Nutr. 2010;7:1-43.
2. Dunford M, Coleman EJ. Ergogenic aids, dietary supplements, and exercise. In: Rosenbloom CA, Coleman EJ, eds. Sports Nutrition: A Practice Manual for Professionals. 5th ed. Chicago, IL: Academy of Nutrition and Dietetics; 2012:128.
3. Fink HH, Burgoon LA, Mikesky AE. Practical Applications in Sports Nutrition. 2nd ed. Sudbury, MA: Jones and Bartlett; 2009:234-279.
4. Sizer FS, Whitney E. Nutrition Concepts and Controversies. 12th ed. Belmont, CA: Brooks Cole; 2011:400-406.