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Do you know what your sports supplement is?

performance enhancers

By Sheila Tucker, MA, RD, LDN
Administrative Dietitian, B.C. Dining

pills_new Would you ever think of volunteering for medical research and sign on to ingest foreign substances to see what they might do to you? If you answer a quick 'no' but are taking a sports nutrition supplement, you may be surprised to learn that you already are a human guinea pig.

Dietary supplements (which include sports supplements, herbals, vitamins & minerals, weight loss supplements and the like) are sold without requirement for Food & Drug Administration (FDA) pre-market approval for safety, purity or efficacy. Additionally, rigorous scientific research on these supplements as a whole is largely deficient or nonexistent and little of the existing research tests for long-term effects. Now add to that the never-ending athletic quest for the competitive edge, toss in a few celebrity icons touting supplements and soon you have a recipe for a large scale observational human experiment on sports supplements where the subjects actually pay to take part, and don’t even know that they are guinea pigs. No wonder the supplement industry is a multi-billion dollar enterprise.

Anyone choosing to take a dietary supplement needs to be as well informed as possible about what they are taking. Those competing at the college level need to know that the NCAA closely regulates the use of dietary supplements and bans the use of most (See: Here are some suggestions, information and resources to help stay up-to-date on sports supplements:

There are several different informal categories of sports supplements marketed for various effects that have athlete appeal. Energy boosters, fat burners, muscle gainers and work-out recovery enhancers make up the main categories.

Energy Boosters and Fat Burners

Most supplements marketed as energy boosters claim to either provide quick energy or delay onset of fatigue (or both). Those which contain plain old carbohydrates as the key ingredient will fit the bill of providing energy and delaying fatigue when consumed as part of an overall healthy training & fueling program. Sports drinks, gels, bars and powders are quick and easy ways for an athlete to supplement the carbohydrate from real food in their diets or during a work-out; they are not substitutes for food nor do they fix a bad diet. Two energy bars and a bottle of a sports drink are not breakfast and lunch. A bowl of cereal, a piece of fruit or some crackers or pretzels can provide a less expensive, great carbohydrate snack before a work-out. Carbohydrate-containing sports drinks are appropriate hydration vehicles for those exercising for over an hour at a stint, or during tough resistance training to keep up important blood glucose levels.

A newer family of energy-boosters is emerging where fancy labels and jazzy adjectives aim to grab attention and sales. Known as energy drinks and energy pills, most contain plant-based stimulants with a dash of other additives. Labels promise a 'rush' or maybe 'endurance'; some irresponsibly are featured in bars and infer a quicker recovery from the effects of alcohol when made into a mixed drink.

Drink versions generally get their 'boost' feeling because they contain some form of caffeine combination (caffeine, guarana or Brazilian cocoa, mate´, gotu kola, green tea) and some carbohydrate. Caffeine amounts are generally not included on the label and vary. This fact could put the college (or Olympic) athlete unknowingly at risk for a positive caffeine test if they have already consumed other caffeine sources during their day. While some studies have reported increased exercise time to exhaustion with small amounts of caffeine, there is no increased benefit seen with increasing amounts. The jitters, rapid heart beat and diuretic effects of excess caffeine are all unwelcome side effects which can ruin athletic performance. Do not be fooled into thinking that herbal forms of caffeine are any more natural or safe for the body. Other drink ingredients include minute amounts of amino acids, the building blocks of protein, and insignificant amounts of vitamins or minerals. Some contain additives with no know benefit, such as pyruvate, bee pollen or trace amounts of herbs, such as ginseng. See: Gatorade Sports Science Center for an excellent synopsis on these drinks and more particular information on specific brands.

Pill forms of these 'energy boosters' also contain plant-based stimulants, sometimes more than one. Caffeine or caffeine-like substances contained in the energy drinks are also in the energy pills. Ephedra, or ma huang, is an herbal stimulant contained in some of these supplements. More recently, ephedra is under closer government scrutiny due to reports of harm and deaths potentially associated with its use. Ephedra is a central nervous system stimulant and therefore accelerates heart rate & blood pressure among its other effects. While you may feel the 'boost', you may also feel the hypertensive crisis or stroke as individual tolerances to ephedra compounds vary. Studies on the ephedra potency of supplement products available in the US have reported inaccurate and unreliable labeling is occurring; some products contain more ephedra than stated on the label while some contain less or none. Self-medicating with such a potentially dangerous and unpredicatble substance is not recommended.

Stimulant 'stacks' containing caffeine, ephedra and aspirin or willow bark fall into the 'energy booster' category and are also marketed as 'cutters' or 'fat burners' in the bodybuilding world. The combination of caffeine and ephedra with aspirin, or aspirin-like willow bark, potentiates the central nervous system stimulation effect of these products. They become potentially more dangerous together because their action is magnified. Medical reports exist detailing life-threatening side effects occurring from these products when used by healthy people young and old. To read more about ephedra and similar stimulants see the FDA’s web site.

Other supplements marketed as 'energy boosters' include ginseng, bee pollen, Coenzyme Q-10 and pyruvate. Research on the effects of each of these on exercise performance has yielded no benefits. Ginseng may interfere with some medications and alter blood clotting. Taking herbs & other supplements in combination with medications is unwise without first consulting a pharmacist and your primary healthcare provider.

Muscle Builders

Muscle-building supplements are a hot market for manufacturers. On-line supplement stores carry bucket-loads and tubs of a variety of products with animal or hormone-like names to entice the consumer looking to get big and powerful.

Protein Powders

Protein powders are available in a variety of flavors and from various sources (milk or soy mostly) to be whirled in the blender into a mega-drink. It does take extra protein to make new muscle ( about 1.4gm-1.8 gm/ kg of body weight vs. the normal 0.8 gm/ kg), but the protein source need not be so expensive nor is a mega-drink needed. High-protein foods contain other important nutrition not always found in a supplement. Plus, to make new muscle, you need more calories, too; better to get all that from real food. Current research proving the superiority of supplemental protein over food sources for muscle gains is pretty sparse. Most protein powders have not been tested for efficacy.

See below for a price comparison on protein sources. Brand X & Y are disguised names for real products available on-line. Someone looking for an extra 50gm of protein per day will pay an extra $730/ year for the supplements over the cost of real food and not come away with anything more to show for it, just an empty wallet.

Protein Source Grams protein/svg Cost/serving Cost/gm of protein
Brand X Whey Pro 7 per scoop 0.39 0.06
Brand Y Super Pro 43 per 2 scoops 2.50 0.06
Skim Milk 8.4 per cup 0.18 0.02
Chicken Breast 23 per 4-oz 0.50 0.02

Amino Acids

The body uses amino acids as the building block for protein, including muscle. The essential amino acids are ones the body cannot make on its own and an outside source is required. Both plant and animal sources of proteins contain an abundance of essential amino acids and most people get enough through diet. Research on amino acids focuses on purported stimulation of growth hormone and improved recovery from intense work-outs. Results are mixed. In athletes who follow a healthy training diet, little effect can be found for the amino acid glutamine, touted for preserving glycogen (stored carbohydrate) stores. Amino acids, arginine and ornithine are marketed as stimulators of growth hormone, but claims are unsubstantiated. Amounts in supplements approximate the arginine in 3-oz of hamburger or salmon or 1-cup chickpeas. All that has not stopped supplement manufacturers from trying to convince consumers that a little more arginine or glutamine or whatever is the solution to all that ails them.

Small amounts of aminos are turning up in energy drinks; you can also buy larger amounts in powder and pill form. Manufacturers list amino acid amounts in milligrams and it looks impressive; remember 1,000 milligrams of an amino is only 1 gram of protein. So, that glass of milk had 8,400mg of amino acids!


Creatine is a substance manufactured in the body from amino acids or obtained from animal proteins in the diet. There is some evidence that creatine use can be effective for repetitive, short-burst activities like sprinting or resistance training. During these anaerobic activities, the body is looking for quick sources of ATP (adenosine triphosphate) for energy. Creatine provides a missing piece of the puzzle by donating its phosphate to adenosine diphosphate to make ATP. While creatine most likely is not directly responsible for increased muscle mass, it allows for a more energized work-out, which in turn may lead to muscle gains from improved training. Vegetarians have had increased results from creatine use compared with those who consume meat; this may be related to differences in baseline creatine intake. There is not conclusive evidence that creatine use for aerobic types of exercise helps performance.

Side-effects are a problem for some taking creatine. Muscle cramping and a bloated feeling may be a result of water shifts that occur in muscle due to creatine concentration. Weight gain can occur from water retention as well. Product labels often advise following a 'loading' schedule where creatine dose is higher, followed by a lower maintenance dose in subsequent days. However, there is debate that a loading regimen needs to be followed.

Many creatine products are marketed with additional ingredients added. Herbs, 'fat burners' and amino acids are some. Creatine is also available in liquid form with add-ins. Efficacy and safety of these combination products is largely untested.

The long-term effects of using creatine are not known. The FDA has advised consumers to check with their physician before choosing to take creatine. Care must be given to stay well-hydrated and to not exceed maximum dose. Additionally, creatine should not be used with any medications that have effects on kidney health, including nonsteroidal anti-inflammatory medications. Despite what benefits there may be for short-term performance, consideration should be given to long-term health.


Androstenedione and dehydroepiandrosterone (DHEA) are called prohormones because they are metabolic precursors to the male hormone testosterone. Androstenedione, or “andro” to friends, is purported to build muscle because of a supposed ability to increase testosterone production. It has become increasingly popular due to celebrity athlete endorsement. Research on androstenedione has not turned up accolades for its muscle-building ability. In a study published in the Journal of the American Medical Association, athletes who took 'andro' for 8 weeks and weight-lifted had no more improvements in muscle mass than those who weight-lifted only. Additionally, those on “andro” experienced a drop in HDL (good) cholesterol and an increase in estradiol, a female hormone. Androstenedione also can cause an athlete to test positive for steroid use because of contaminants in mislabeled products and metabolite production.

DHEA is naturally made by the body, but production declines with age. Some claim it can be used to delay the effects of aging and to enhance body composition. There is no evidence that DHEA supplementation prevents aging. In fact, DHEA may increase reproductive cancer risk; results are not conclusive. Research on DHEA and body composition has not borne out any benefit to its use.

Like many supplements, long-term effects and safety from using prohormones are unknown.

Other Muscle Builders

A variety of other supplements are available that tout their muscle-building power. Many of them are plant-based and rely on their “naturalness” for a marketing angle, claiming they are able to be converted naturally to steroids by the body. Often, supplements offer a mix of these substances with added prohormones or protein powder or vitamins. Yohimbe, gamma-oryzanol, wild yam, tribulus terrestris, smilax and others all fit this category. There is insufficient scientific research on these substances to report on safety or efficacy. Yohimbe may negatively interact with some medications and also cause blood pressure elevation. No long-term effects are known for these supplements.

Regulations and Safety Cautions

It’s buyer beware for dietary supplements. Without mandated pre-market approval, consumers need to use caution when choosing to use a supplement. A study on ephedra products in the US found that many had inaccurate label statements on ephedra content; some even varied lot-to-lot for a given brand. Reports on other herbal supplement potency and labeling have yielded similar results. No testing or screening is done by the FDA as to potency, possible contaminants, label accuracy or safety. Supplements have been shown to contain substances not listed on the label as well as inaccurate dosing. Competitive athletes would be unwise to chance taking any supplements, outside of sports drinks or carbohydrate replacement, for fear of violating any NCAA or International Olympic Committee (IOC) regulations. Recreational athletes would be wise to take a hint from these regulations.

If You Choose...

If you do choose to take a supplement, follow these safety guidelines:

  > Realize that relatively little research is available on most supplements.
  > Know that long-term effects are mostly unknown for the majority of supplements.
  > Remember that label claims on products can be vague and hint at claims that are unsubstantiated.
  > Supplements with a USP seal on the label can be better trusted for content (what the label says is in the product actually is!) The USP seal does NOT mean that label claims are tested or true.
  > 'Natural' is not synonymous with safe. Arsenic and hemlock are 'natural'!
  > Stop taking any supplement if you experience side-effects. Report serious side-effects to FDA MedWatch at
  > Consult with your primary healthcare provider about the safety of using supplements for your individual concerns, including drug interactions or effects on medical conditions. Don't ask the sales clerk in the supplement shop.
  > Ask a registered dietitian (RD) about any dietary supplement and what is known about its effects and side-effects. Use the links in this article to do some homework of your own, too.


New Window: Gatorade Sports Science Institute
New Window: American College of Sports Medicine
New Window: NCAA Nutrition and Performance
New Window: Australian Institute of Sport
New Window: FDA guide on supplements
New Window: National Institute of Health Office of Dietary Supplements