Sports Supplements

With claims such as "supplements will make you stronger, faster, leaner or healthier" it is no surprise that annual supplement sales are sky high. In South Africa alone, the annual turnover of the supplement industry, including sports products, is approximately R1.5 billion a year.

It is also important to note that black market sales of supplements (ie. those containing banned substances) are big business. These sales are reported to be more than $100 million per annum in the United States. If so many people, especially athletes, are prepared to spend so much money on supplements, surely there must be a place for supplements in sports performance?

The truth is that very few supplements match their promised claims of improving sports performance, increasing strength and power, enhancing the immune system, reducing body fat etcetera. Yet every year new products and formulas hit the shelves with even stronger marketing messages. Since the supplement industry is uncontrolled and poorly regulated, many of the claims made about these products are not backed by scientific evidence. In addition, you can never be 100% sure that the ingredients listed on the label, are in fact present or are present in the quantities stipulated on the label of the powder, pill or liquid that you are buying. Some of these supplements may also be contaminated with banned substances (eg. anabolic steroids and certain stimulants). This may be inadvertent or in some cases even deliberate to produce the effects claimed. However, even if supplements are contaminated deliberately, some or these substances only work if injected and thus the oral over-the-counter products that contain only the precursors or breakdown products of banned substances may not have a performance-enhancing effect. This risk for contamination is especially high in those supplements that promote fat-burning and/or muscle-building effects. Examples of prohibited substances found in nutritional supplements are DHEA, Ephedrine, Amphetamines, and Androstenedione. Competitive athletes are advised to refer to the Athlete's Handbook, published by the South African Institute of Drug-Free Sports, which is updated on an annual basis.

Nutritional supplements that have the potential to enhance performance

Certain nutritional supplements, if used correctly, can play a small but important role in enhancing sports performance. It is important to note that these supplements only form the 'tip of the iceberg' when it comes to winning gold. Proper training, good skill and technique, adequate sleep and rest, equipment, sound nutrition and mental attitude still form the basis of optimal sports performance.

The supplements discussed in this article are those nutritional supplements that have the potential to improve performance if used correctly.

Carbohydrates 

Carbohydrates are probably the most basic, yet important nutrition supplement for people engaging in physical activity. Carbohydrate supplements provide a concentrated source of energy (mostly in the form of glucose polymers), are practical to use and are available in liquid, gel, powder and solid forms. Maltodextrins are glucose polymers that provide a mild sweet taste, have a fast stomach-emptying rate and are well tolerated by the majority of athletes. Unflavoured glucose polymer powders are also available and can be added to water or other drinks and beverages. Many sports drinks, corn syrup gels, sports bars and various other sports products contain glucose polymers and can be ingested before, during and after exercise.

Impact/Claim: Carbohydrate is the preferred fuel during exercise and is crucial for the muscles to perform work. If the body runs out of carbohydrate, the muscles will stop working. Research has conclusively shown that enough carbohydrates need to be eaten before, during and after exercise for optimal performance (see articles on carbo-loading and carbohydrates and exercise).

Side effects: If used correctly carbohydrate supplementation is safe. High concentrations of carbohydrate drinks and drinks containing fructose may cause stomach upset during exercise (see article on carbohydrate and exercise) and overuse of carbohydrate supplements may lead to weight gain.

Protein powders

Protein powders provide high quality protein or protein isolates that can be effectively absorbed by the body. The milk proteins, casein (protein responsible for making the curd) and whey (left behind after the curd is removed) as well as egg albumin are popular dietary proteins. Relative to other protein sources, whey protein has a high concentration of specific important amino acids is absorbed very fast and effectively. Popular components of whey proteins that you will see on protein powder labels include, amongst other, bovine serum albumin, lactoferrin, immunoglobulins and lactose. The common commercially available form of whey includes whey protein isolate (90-95% protein) and whey protein concentrate (usually 80% protein).

Claim/Impact: Protein powders are claimed to prevent muscle loss, improve muscle mass and strength and help the recovery process after exercise, making the athlete stronger and fitter. Certain amino acids are also claimed to enhance the immune system and improve performance by increasing muscle mass and providing additional fuel. Protein supplementation may prevent muscle loss if an athletes' diet is too low in protein and energy to start with, but additional protein supplementation alone is not beneficial to performance. Practically, protein supplementation can help an athlete achieve optimal protein intake from a low fat, highly absorbable source, IF the athlete is not consuming enough protein already (ie. vegetarian athletes). If lesser amounts of protein are required, adding fat-free milk powder to food (eg. porridge/cereal/mashed potato) or drinks is a practical, affordable way to top-up protein requirements (see article on protein and exercise).

Side effects: Consistent, excessive high protein intake may have various negative health effects, including kidney damage, as well as an increase in fluid losses. It may also contribute to gout, arthritis and an increase in fat mass.

Recovery formulas

Recovery formulas are fluid-based formulas that contain a mixture of protein and carbohydrates (some formulas may also contain a little fat, added vitamins and minerals as well as specific amino acids such as glutamine).

Claim/Impact: Recovery formulas should be consumed directly after exercise and are claimed to speed up recovery. Research has shown that sufficient carbohydrates taken together with protein enhance the recovery of muscle energy stores as well as the muscle structure itself (see article on protein and exercise). Glutamine plays an important role in the immune system and is used as a fuel by the immune cells. During exercise, more glutamine is used by the body, thereby decreasing glutamine concentrations. Replacing glutamine straight after exercise to restore glutamine levels is claimed to keep the immune system strong and aid in recovery. However, glutamine supplementation has not consistently been shown to improve immune function.

Side effects: Although recovery formulas are safe to use, as with other sports supplements, there is still a risk that these formulas may be contaminated with banned substances.

Creatine

Creatine is the most popular sports nutritional supplement on the market. Creatine is naturally synthesized in the body from amino acids and is stored in the muscle. Creatine is the primary source of ATP (usable energy) in the muscle during intense burste-type exercise. Certain food sources such as fresh meat and fish also contain small amounts of creatine. Creatine is also available in many over-the-counter products as a powder, pill or liquid and is sold in health shops, pharmacies and sports shops. The 2 most effective supplementation regimens include a rapid-loading protocol for 5 days (loading dose = 20g creatine per day, divided into 4-5 dosages of 4-5g per dosage and taken with 50-100g of high-GI carbohydrates), or a slow-loading protocol for 14-21 days (loading dose = 3-5g creatine per day, taken with 50-100g of high-GI carbohydrates).

Impact/Claim: Creatine supplementation is claimed to improve performance as a result of increasing energy availability and the ability to train more and recover faster. There is scientific evidence to support creatine's performance-enhancing effect on short-duration, repetitive maximal effort events such as short sprints and 1 Repetition Max. Creatine supplementation may result in muscle mass gain, does not enhance endurance and is thus not beneficial for endurance events. Not everyone responds to creatine supplementation and people younger that 18 years should not use creatine supplements.

Side effects: Short-term supplementation with creatine seems to be safe, but more research needs to be done to investigate the effects of long-term supplementation. Isolated cases of possible renal side effects have been reported, but the evidence is not conclusive. General side effects include water retention, weight gain and increased muscle compartment pressure that could possibly cause muscle cramping.

Beta-Hydroxy-Beta-Methylbutyrate (HMB)

Beta-Hydroxy-Beta-Methylbutyrate (HMB) is an amino acid metabolite that is synthesized in the body.

Impact/claim: HMB is marketed to suppress protein breakdown in the recovery phase after a workout. HMB is further claimed to increase lean-body mass and strength. Although HMB supplementation may improve upper body strength slightly in untrained individuals, there is little evidence that HMB increases fat free mass and performance in well-trained athletes. HMB is available in many over-the-counter nutritional supplements and may also be combined with other substances like creatine.

Side effects: HMB supplementation appears to be a 'safe practice', but once again there is a risk that the HMB supplements may be contaminated with banned substances.

Caffeine

Caffeine is one of the most widely consumed drugs in the world, taken socially and for its alertness- and performance-promoting actions. Caffeine can be classified as a stimulant that acts on the central nervous system. Caffeine and caffeine-like substances can be found in a variety of foods and drinks. The most popular sources of caffeine include coffee, certain teas, cocoa and drinks such as Coca-Cola" and Red Bull".

Impact/Claim: Because of its stimulant properties, caffeine supplementation is claimed to increase alertness, mask fatigue, enhance fat metabolism, spare muscle glycogen, and as a result improve performance. If ingested before an endurance event, and on an empty stomach, caffeine supplementation has a potential performance-enhancing effect by sparing muscle glycogen, however, this has to be weighed up against the potential negative effects of not taking carbohydrate. Some studies have reported performance-enhancing effects even with low dosages (3mg/kg) while other studies only showed a performance-enhancing effect at dosages of 6-9mg/kg. Individuals respond differently - a person who regularly consumes caffeine may not benefit from caffeine supplementation, while someone who never consumes caffeine may respond well to low dosages. Athletes therefore need to experiment with caffeine ingestion to find the optimal dosage particularly since there may also be unwanted side effects that could negatively affect performance.

Side effects: Side effects can include anxiety, gastrointestinal distress, headaches, elevated blood pressure, nervousness, anxiety, dependency and withdrawal. Although caffeine is a diuretic, its diuretic effects are overridden during exercise.

Legal or not? Caffeine is currently not banned by WADA (World Anti-Doping Agency)