Many supplements may contain banned substances and there is a chance that not all the ingredients are accurately listed on the label of a supplement product, warn sports nutritionists Shelley Meltzer and Cecily Fuller from the Sports Science Institute in Cape Town.
To protect sportspersons from using banned substances and to help them in the correct use of nutritional supplements, this practical guide can equip sportspersons with the tools to make decisions about nutritional supplements.
Brand names (other than food-based products) are not given since an independent regulatory body is unable to guarantee the contents of any supplement products.
Supplements in perspective
Supplement use should be individual-specific and sport-specific. Certain nutritional supplements, if used correctly, can play a small but important role in enhancing sports performance. However, it is important that the use of nutritional supplements be based on a solid foundation incorporating other factors vital in achieving peak performance. If any of these factors are lacking, then any potential performance benefit from nutritional supplements will be lost.
Sportpersons can make use of a classification system to establish the benefit or risk to be gained from a nutritional supplement. This system is based on the weight of scientific evidence supporting that particular supplement and has been adapted from that currently used at the Australian Institute of Sport.
Note: new scientific evidence may emerge which could shift supplements between groups in the classification system.
Here are all the "legal" supplements according to Supplement grouping, definition and specific supplements:
This group includes supplements and sports foods that provide a performance benefit in sport-specific and individual-specific situations or provide a useful and timely source of energy and nutrients in an athlete's diet or are of medical/therapeutic benefit.
Specific examples: bicarbonate, beta-hydroxy-beta-methylbutyrate (HMB), creatine, calcium, carbohydrate powders and gels glucosamine and chondroitin, intramuscular iron, intramuscular vitamin B12, liquid meal replacements, melatonin, recovery formulas, sports energy bars skim milk powder, sports drinks, specific vitamins and minerals.
This group includes supplements currently lacking substantial proof of beneficial effects or have no proof of beneficial effects in sportspersons. This group contains the majority of supplements including many herbs and herbal extracts* promoted to sportspersons. These supplements enjoy a cyclical pattern of popularity and use, but have not been proven to enhance sport performance. In some cases these supplements may impair sports performance or health.
Specific examples: arginine, bee pollen, branched chain amino acids (BCAA’s), colostrum, CLA (conjugated linoleic acid), carnitine, cordyceps, cytochrome C, coenzyme Q10, chromium picolinate, choline, Echinacea, ferulic acid, ginseng, glycerol, glutamine, ginkgo biloba, gamma-oryzanol, intravenous iron, inosine, lysine, network marketing supplements including Herbalife and Amway, ornithine, pro-biotics, Protivity (Microhydrin), pyruvate, ribose, vitamin B12 injections, spirulina.
Supplements that are prohibited for use by the International Olympic Committee. This list includes prohormone supplements and stimulants.
Adapted from the Australian Institute for Sport Supplement Classification System.
* Herbs and herbal extracts in this context refer to plants or plant extracts ingested for reasons other than caloric or culinary benefit. Currently there is a lack of dose-response data in athletes and the interpretation of studies is complicated by the varying combinations of herbal extracts and active components used as well as the variability in growing conditions. Most studies are of limited duration and it is difficult to detect small improvements to performance especially when effects may be chronic rather than acute. A further concern is that many herbals contain unstated ingredients on labels and may inadvertently contain ephedra or other herbal alkaloid stimulants.
Category A nutritional supplements
|Type of supplement||Dose/composition||Rationale/sport-related use||Concerns/safety/side effects|
|Broad spectrum multi-vitamins and mineral supplements||1-1.5 x RDAs of vitamins and minerals||Support for low energy or weight loss diets, restricted variety diets, unreliable food supply (e.g. travel)||In absence of deficiency may not improve performance|
|Liquid meal replacements (e.g. Ensure, Nestle BuildUp, Complan, Nutren 1.0)||1-1.5 kcal/ml; 15-20% protein, 50-70% carbohydrate, low to moderate fat, vitamins and minerals – 500-1000 ml supplies RDA)||Easily prepared meal replacement for lack of appetite, high energy requirements, weight gain, weight management for weight-making sports (1-3 days pre-weigh in), low bulk pre-event meals, post-exercise recovery, travel, injury||Over-reliance may lead to inappropriate replacement of whole foods|
|High protein meal replacement formulae||42-55% protein; 25-35% carbohydrate; low fat to fat free (varying vitamins and minerals)||Easily prepared meal replacement for athletes not able to meet protein needs via food (e.g. some vegetarians); or for athletes with additional protein requirements (e.g. growth spurts; injury)||Expensive. May inappropriately replace whole foods or may displace carbohydrates; risk of protein overload; may lead to excess body fat|
|Skim milk powders(e.g. Elite, Protea, Klim)||35% protein; 50% carbohydrate, fat-free (may have vitamins added)||Economical and ideal to use to fortify food and drinks for weight gain, recovery, lack of appetite|| |
|High carbohydrate supplements |
High carbohydrate sports drinks
Sports Bars (e.g. Energade Bars; Powerbars)
Cereal bars (e.g. Bokomo
|Sports drinks (5-7% carbohydrate 10-25 mmol sodium, 3-5 mmol potassium) |
10-25% carbohydrate concentration with added electrolytes
Gels (30-40g sachets: ~25g carbohydrate/sachet, electrolyte, vitamin and mineral content varies.
Powders (glucose polymers - flavoured or plain), may have added vitamins, minerals.
Bars: 50-65g bar: 40-50g carbohydrate, 5-10g protein, low fat, low fibre (may have added vitamins and minerals).
Per 30g bar: 16-25 g carbohydrate, 1.5-2 g protein; 1-5 g fat; 1-2 g fibre (may have added vitamins and minerals).
|High carbohydrate requirements e.g. heavy training, carbo-loading, pre-, during and post-exercise, weight gain, lack of appetite. |
Convenience (portable) powders can be mixed to desired concentrations or added to food/drinks.
Gels provide easily digested carbohydrate for sports with lower fluid requirements or when it is impractical to eat whole foods.
Bars are a compact source of energy and are non-perishable. The lower fibre bars are useful for athletes who experience gastro-intestinal problems during exercise.
|Overuse may lead to weight gain or disturb the ratio of macro-nutrients. Gastro-intestinal upset if concentrations are too high (e.g. powders, some gels). Gels should be consumed with adequate fluid to meet hydration needs. These products may contain other compounds that may not be safe/legal (e.g. caffeine) or that may cause gastro-intestinal problems (e.g. medium chain triglyceride).|
|Protein supplements (e.g. Whey powders)||Varying concentrations (30-80% protein by weight)||Weight gain (but needs to be consumed with adequate carbohydrate) |
|Expensive, may be unnecessary if balanced diet with appropriate calories is consumed. Inappropriately used it can lead to fat weight gain and calcium excretion.|
|Recovery formulas||60-67g carbohydrate (low or high glycaemic index carbohydrates); 10-30g protein (whey, cassein and soy); electrolytes (sodium and potassium).||Convenient source of rapidly absorbed carbohydrate and low fat protein to stimulate energy storage and repair of damaged muscle. Sodium and potassium help maintain electrolyte balance and improve hydration.||Choose according to individual taste, preference and tolerance. |
Timing: Should be ingested within 40-60 minutes of completing exercise to optimise the uptake of essential nutrients.
|Bicarbonate||0.3 g sodium bicarbonate per kg body mass (~ 20g) 1 hour pre-event + 1-2 litres water (can reduce subsequent doses if participating in heats or finals on same or successive days).||May benefit if performing intense activity lasting about 10 seconds. The bicarbonate binds with hydrogen ions and prevents acid build up.||Gastro-intestinal upset: should be practised in training to assess benefits and side-effects.|
|HMB (beta-hydroxy-beta-methylbutyrate)||1.5g – 3g per day||In the early stages of training may reduce the amount of exercise-related muscle damage (mechanism unknown); small reduction in body fat %, small increase in muscle mass gain. |
May have an additive effect on body composition when combined with creatine.
|No recognised side effects; results from long-term studies still needed.|
|Sick packs, immune boosters, anti-oxidants||Antioxidant combinations (e.g. 18 mg beta-carotene, 500-1000 mg vitamin C and 60-350 mg vitamin E), glutamine (5-8g/day) and zinc (50mg/day). |
To be used short-term (5-7 days).
|Use short-term to boost immune function during periods of intense training and altitude training.||Excessive and continuous intake of these nutrients may be counter-productive and damage health.|
Category A Medical supplements
|Vitamin B12||For treatment of pernicious anaemia. May be used as a prophylactic in some vegetarians. May be necessary after gut surgery. |
|Proper assessment of risk factors; no proven performance enhancement effects unless pre-existing deficiencies.||Rare allergic reactions to B12. Excessive intakes of some vitamins may impair the absorption of other nutrients; some vitamins at high intakes can be toxic.|
|Iron||Ferrous sulphate/gluconate/fumarate. |
100-300 mg elemental iron/day for 3-6 months with ongoing monitoring.
Vitamin C increases iron absorption in gut (may be prescribed with 500mg Vitamin C and/or with folic acid).
|Only if proven iron deficiency on blood tests. Risk factors for deficiency include: vegetarian diets, heavy menses, low energy diets.||Gastro-intestinal upsets; constipation; haemochromotosis; may interfere with zinc and copper absorption.|
|Calcium||Calcium carbonate/phosphate/lactate. |
500-1000mg/day depending on dietary intakes usually taken between meals or at bedtime.
|Calcium supplementation in a low-energy or low dairy food diet; treatment or prevention of osteoporosis.|
Calcium supplementation does not guarantee bone status in absence of adequate eostrogen/progesterone status. Will not correct poor diet.
Note that calcium supplements should be combined with vitamins D and K2.
|Glucosamine sulphate and chondroitin sulphate||800-1500 mg/day glucosamine sulphate. |
200 mg chondroitin sulphate.
For minimum of 3 months
|Repair of articular cartilage; glucosamine has mild anti-inflammatory properties.||Proven benefit in treatment of ostoearthritis (hip and knee). No evidence of benefit in athletes without cartilage damage. Long-term effects are still unknown.|
|Melatonin||3 mg stat (for sedative effect) |
3 mg daily for 5 days (to restore diurnal rhythm)
|Main benefit is to restore the normal diurnal rhythm (recognition of night and day). Mainly with eastward flights. Sedative effect variable and large individual differences.||May cause headache and dizziness. Should not be used with sleeping pills, warfarin, or by those with a history of migraine or epilepsy. Allergic reactions occur in 1/240 users of melatonin.|
RDA = Recommended Dietary Allowance
Note: branded food products cited in the table are merely examples and are by no means an endorsement of the product.
Conclusions and recommendations
- Supplements should only be taken when there is proof that the diet cannot provide the quantities of nutrients needed. A nutritional evaluation by a dietician (with sports nutrition experience) should determine if any deficiencies are present in the diet and supplements can be supplied accordingly. This evaluation should take into account body composition goals, dietary and medical history, food practices and preferences, training and competition nutrition requirements and budgetary constraints.
- Dosages of supplements need to be calculated to avoid overdose.
- Individuals may respond differently to supplements and this needs to be taken into consideration. For example, 30% of athletes may not respond to creatine supplementation and supplements may be tolerated differently by different persons. Try and test diet and supplement changes well before a major competition.
- Supplements required in clinical situations require a proper medical diagnosis and again should only be prescribed by the sports physician and dietician in writing. Athletes are also reminded to request written prescriptions for supplements. Fitness coaches and conditioning staff should not prescribe any supplements.
- No persons under the age of 18 should take any sport-specific supplements without the advice of a sports physician or dietician.
- All supplement labels should be carefully studied and the ingredients noted. Look for hidden relationships between ingredients (e.g. caffeine and guarana), unstated ingredients (e.g. fat-burning supplements that may contain hidden banned stimulant products) and avoid the prohormone supplements that are banned by sporting federations.
- We recommend that for every supplement purchased the athlete request the supplier to provide a quality control certificate (this should demonstrate that the product has been tested at an independent IOC accredited laboratory and has been shown to be free of prohibited substances). The supplier should also provide legally binding documentation listing all contents of ALL the different products that they produce and should accept full liability for a positive doping test as a result of the use thereof. This guarantee document should:
- Be on a company letterhead.
- Be signed by management and dated.
- Include contact details for the person responsible for issuing the guarantee.
- Address the athlete directly by name, and not generally e.g. "To whom it may concern".
Compiled by Dr Ryan Kohler, Mrs Shelly Meltzer RD (SA), Dr Ismail Jakoet and Professor Tim Noakes for sarugby.net.