Children 10–18 years

Sports supplements should be taken with care

Vending machineAs athletes seek to gain a winning edge in performance the pressure to reach beyond their own physical capabilities, by using dietary supplements, can be immense.

While some supplements are well recognised as being useful to performance others can lead to positive drug testing and disqualification as well as endanger long-term health.

There is growing concern that cheap dietary supplements are now readily obtainable by athletes and coaches over the internet. This raises the risk of unintentional doping, through the consumption of contaminated substances.

So what supplements are available and how safe are they? What group of athletes use them and why? Also how big is the problem of doping and what can parents, coaches and team managers do to safeguard the health and integrity of young athletes and protect the interests of fair play and clean sport?

Dietary Supplement Classification

The Australian Institute of Sport (AIS) has developed a classification system (ABCD) to enable athletes to have greater clarity regarding the safety of dietary supplementation. This system ranks sports foods and supplement ingredients into four groups based on scientific evidence and practicality that determines whether a product is safe, legal and effective in improving sports performance 1

In 2014 this program was extended to include a third party auditing and batch testing system which focuses on sports foods and individual ingredients rather than supplement products and brands.1 This aims to protect athletes from products being marketed to them through promotion and distribution networks that ignore the need for a scientific evidence base and also from the use of multi-ingredient products that may contain an undefined proprietary blend or recipe of individual ingredients, the dose of which may be undefined.

The ABCD classification system

Group A
These products have evidence –based protocols to support their use in specific sports situations and are used within a supplement program. These include three groups:
Sports foods e.g. sports drinks, gels, bars; liquid meals; whey protein and electrolytes etc.
Medical supplements– e.g. iron, calcium, multi-vitamin/mineral and vitamin D.
Performance supplements-e.g. Caffeine, B-alanine, Bicarbonate, Beetroot juice, Creatine

Group B
This group of supplements are undergoing further research and only administered within a research or case-managed monitoring system.
Food polyphenols– e.g. Quercetin, Tart cherry juice, Exotic berries (acai, goji etc.) Curcumin. Also anti-oxidants C and E, Carnitine, HMB, Glutamine, Fish oils and Glucosamine.

Group C
This group has little meaningful proof of beneficial effect and covers supplements not listed in the A, B and D categories. Such products are only permitted for individual athletes under the supervision of a sports supplement panel.

Group D
These are banned or at high risk of contamination with substances that could lead to a positive drug test and should not be used by athletes:
StimulantsWorld Anti-Doping Agency (WADA) list e.g. Ephedrine, Strychnine, Sibutramine, Methylhexanamine (DMAA) other herbal stimulants
Prohormones and hormone boosters (WADA list) e.g. DHA, Androstenedione, 19-norandrostenione/ol other prohormones, Tribulus terrestris and other testosterone boosters, Maca root powder.
Growth hormone releasers and ‘peptides’ -(WADA list) These are sometimes sold as supplements but are unapproved pharmaceutical products
Others– (WADA list) e.g. Glycerol used for re/hyperhydration strategies banned as a plasma expander; Colostrum- not recommended by WADA due to inclusion of growth factors in its composition.
Note-More details and handouts on individual products are available 1

The risks associated with supplementation

All sports supplements carry some risks and they should never be taken as a substitute for good nutrition.2

Sports drinks, bars, gels and recovery drinks

These are a convenient way for athletes to increase their energy intake. However, because they are a major source of refined sugar, they should not be used routinely as snacks, but rather as part of an overall sports nutrition plan that is tailored to match the age, gender, growth and development of the athlete.
Quantities taken should also reflect the duration and intensity of exercise and reflect the changing energy and nutrient needs of the athlete during training and competition.
Athletes using these products should also be aware that they can be highly corrosive on teeth so their use should be accompanied by water and a greater attention to dental hygiene on a daily basis.

Vitamins and minerals

Are not sources of energy in themselves but rather they take part in complex chemical reactions in the body. Some can be toxic if taken in excess. Athletes should only take these under medical supervision to correct proven nutrient deficiencies.

Muscle bulking agents

These should not be used by adolescent athletes as they run the risk of developing potentially career ending injuries that can be caused by ruptures of the tendonous insertion of over developed muscles into an immature skeleton.2

Banned substances

These not only carry the risk of failed drug testing but they endanger long-term health.
E.g. Anabolic steroids can cause acne, liver abnormalities and tumors, they increase the risk of tendon rupture, increase blood pressure and cholesterol and inhibited growth and development. In men they can cause shrinkage of testes, breast prominence, infertility and impotence. In women they cause a deeper voice, increased body hair growth, enlarged clitoris, baldness and endanger fertility.
Growth hormone treatments cause joint pain, carpel tunnel syndrome, diabetes, hypertension, elevated blood cholesterol and cardiomyopathy.
Erthropoietin can cause stroke, heart attack and pulmonary oedema

The “escalation” factor

Scandinavian research of 212 athletes has found that once using supplements an athlete was 3.5 times more likely to move onto the use of banned substances (22.9%) than non-supplementers (6%). Athletes taking supplements were also more likely to believe doping to be effective in enhancing performance than non-supplementing athletes.3

Some sports are more susceptible to doping

In 2006 a study of 446 athletes in Finland4 found that:

  • 15% had been offered banned substances themselves of whom 21% were speed and power athletes, 14% were team sport athletes involved in motor skill demanding events and 10% were endurance athletes
  • 90% of athletes believed that banned substances and methods could enhance performance.
  • 30% believed they knew athletes who were uses
  • Men were more at risk of taking banned substances (35%) than female athletes (25%).4

Supplement use begins at school

In 2014 a New Zealand survey of 142 senior rugby players (aged mostly 17- 18yrs) in 7 schools 5 found that:

  • 71% reported using 4.4 supplements on either a daily, weekly or monthly basis.
  • 90% were concerned about the safety of supplements and the most popular supplements were protein powders, sports recovery and energy drinks.
  • Supplements were mainly taken to improve muscle size/strength, performance and recovery.
  • 2 players admitted using banned drugs
  • 20% would consider doping to recover faster from injury
  • 10% would consider doping to improve muscle size, looks and performance where this relates to selection and/or winning.
  • 20% of respondents were receiving information about banned drugs
  • 1 in 5 felt they were at risk” of using them.

Who influences athletes the most?

If drug education is to be effective who will athletes listen to for advice?Interestingly in the 2014 New Zealand study respondents identified:

  • trainers and professionals as being the most reliable sources of information on supplement safety, labelling and general nutritional advice BUT
  • the athletes claimed they were more likely to be influenced to take supplements by their family/whanau, coaches, friends and team mates.
  • 54% players said they would report to an official if they knew an opposition member was doping BUT
  • only 42% would report if a team member was using a banned substance.

The researchers noted that both these last results demonstrated an accepted level of secrecy surrounding banned drug use 5

This raises the important issue of the pressure that “group culture” can have over the decisions made by individuals.

Group Culture

There are a number of factors that influence the formation of attitudes that players and athletes may have towards drugs in sport. Many of these attitudes are shaped by the sport’s culture and here are some examples regarding how these may develop:

  • A winning at all costs attitude” can have its roots in childhood 6 if parents (particularly fathers) and authoritarian school sports coaches emphasise the importance of winning at all costs rather than fair play then the possibility of “cheating” may become condoned.6
  • The commercialization of sport has tempted athletes, especially at the elite level; to take performance enhancing drugs (PED’s) in order to drive for their personal best and please family and friends irrespective of the health risks. While athletes may see doping as cheating the pressure to win is great and rewards high. 7
  • Modern sport has become “medicalized and scientized” as, particularly elite, athletes seek help from physiotherapists, biomechanics, physiologists, physiotherapists, pharmacists, nutritionists and psychologist in order to improve performance. This has led to a greater supply of services
    (for advice about technique) and products (equipment, food supplements and drugs).8 While this team approach can be invaluable to athletes it may also increase the pressure to achieve results.
  • Financial incentives increase the pressure to maintain sponsorships and along with media coverage puts pressure on coaches and sporting managers to win. Athletes can also be pressured to acquire as much wealth as possible during their brief and perhaps risky careers. 9
  • Risk taking, particularly by male athletes can become embedded in the culture of sporting clubs where alcohol, recreational substance and tobacco abuse are seen as part of masculinity and manhood 10
  • The desire for status, fame and approval may drive some athletes to doping. In these cases failure, defeat, injury and social stigma of being caught using illicit drugs may be seen as being problematic but allowed so long as they are associated with a heroic outcome. 11
  • Alcohol and binge-drinking has a long association with some sports. While it is unclear where to put alcohol as a behavior altering substance there is increasing evidence of its detrimental impact upon health and performance and can lead onto other risk taking behaviours such as doping. 12
  • Societal pressures, it could be argued, has created a culture of relentless competition and grand expectation that athletes can continue to sustain high performance. This pressure along with an increased development and availability of drugs has resulted in an increase in their use13
  • Team dynamics may add to the pressure as sports that focus on team bonding on one hand but intensive competition on the other makes a fertile ground for drug use and abuse 14

Accidental doping

Regulations controlling supplements in foods varies between countries and there are a large number of sports supplements and foods available world-wide that are not controlled and are marketed on the basis of unsubstantiated and exaggerated claims regarding their efficacy. Industrial hygiene standards and labelling of these products can vary widely. Hence there is concern regarding the purchasing of all types of dietary supplements by athletes over the internet.2

Unfortunately, under the WADA strict liability rule, if an athlete takes a supplement which contains a prohibited substance and this subsequently leads to a positive drug test, it is not an adequate defense to state that the athlete was unaware of the prohibited substance in the supplement ingested. 2

As just one example a study in Ireland found in an examination of supplements bought from a variety of sources that up to 14.8% were contaminated with undeclared substances which were on the WADA prohibited drug list.2

What can parents do to keep athletes safe?

  • Teach them to value their body and uniqueness from an early age.
  • Encourage them to develop their talents not only in sport but a wide range of things e.g. music, art/design, photography, drama etc. This will not only help to boost their self-esteem and confidence on days when their sporting performance may fail them, but can also help to build a buffer zone, of additional friends and contacts outside of sport, for the future.
  • Value healthy eating and lead by example. Encourage children’s natural interest in foods by developing skills such as gardening,shopping, cooking and preparing simple meals and snacks at an early age.
  • Value sports nutrition education and seek professional help. If sporting activities increase to the point that they occupy 2 or more hours per day then consult a Sports Dietitian for guidelines regarding your child’s energy needs. This is particularly important for athletes (of all ages) who may be struggling with their growth rates, regularly feeling fatigued or who suffer from recurrent illness.
  • Encourage young people to talk about their feelings and views on a wide range of subjects including doping, health issues and ethics and to be aware of the work of Drug free Sport NZ14
  • Support clean sport initiatives that extend across all sports from team management (scientific and medical staff), players and coaches through to other parents, sponsors, player unions and fans. In this way you are creating a healthier environment for your child to compete in.

If you would like to know more about how sports nutrition can enhance you or your child’s sporting performance then contact us today.

More reading

For more information on sports nutrition read some of Lea’s other articles


  1. Classification: AIS : Australian sports commission. The ABCD classification System
  2. Supplements and sports food policy. The Irish sports council 2012
  3. Backhouse SH, Whitaker L, Petroczi A Gateway to doping? Supplement use in the context of preferred competitive situations doping attitude, beliefs and norms. Scandinavian journal of medicine & science in Sports Vol 23, Issue 2, 244-252 April 2013.
  4. Alranta A, Alranta H, Holmila J,Palma P, Pietila K, Helenius I, Self reported attitudes of elite athletes towards doping and differences between types of sports. International journal of sports medicine 2006, Oct 27 (10) 842-6 Epub 2006 Feb1.
  5. Curtis A, Sports participation, motivation and performance enhancement survey. In press University of Otago 2014.
  6. StrelanP, Boeckman R. A new model for understanding performance enhancing drug use by elite athletes. Journal of applied psychology 15,176-183 2003.
  7. Mugford, S., Mugford, J., & Donnelly, D. (1999). Social research project: Athletes’ motivations for using or not using performance enhancing drugs. Canberra: Australian sports drug agency
  8. Waddington, I. (2001). Doping in sport: Some issues for medical practitioners. Paper presented at the Leiden International Medical Students Congress, University of Leiden Medical School, Netherlands.
  9. 9 Mahony 2001: Smith A, Stewart B, Oliver-Bennett’s S, McDonald S, Ingerson L, Anderson A, Dickson G, Emery P, Graetz F. Contextual influences and athletic attitude to drugs in sport. Sports management review No 5, Aug 2010, ISSN 1441-3523
  10. Whitehead, A. (2005). Man to man violence: How masculinity may work as a dynamic risk factor. The Howard Journal, 44(4), 411–422.
  1. Petti-Watel P, Beck F, Legleye S. Beyond the U –curve: the relationship between sport, alcohol, cigarette and cannabis use in adolescents. Addiction 2002, June 97(6) 707-16.
  2. Smith, A., & Stewart, B. (2008). Drug policy in sport: Hidden assumptions and inherent contradictions. Drug and Alcohol Review, 27, 123–129.
  3. Smith A, Stewart B, Oliver-Bennetts S, McDonald S, Ingerson L, Anderson A, Dickson G, Emery P, Graetz F. Contextual influences and athlete attitudes to drugs in sport. Sports management review N 5, Aug 2010, ISSN 1441-3523.
  4. Drugfree Sport NZ

About the author View all

Lea Stening

Lea is one of New Zealand’s leading paediatric dietitians and also specialises in Sports Nutrition. She has specialised in Paediatric Nutrition for 31 years and in 1985 was the first paediatric dietitian to enter private practice in New Zealand. Lea helps families through her private consultations, public lectures, newspaper and magazine articles as well as television and radio interviews. Read more »

View all posts by Lea Stening »


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