advertisement
Updated 10 August 2016

Sports supplements for schoolkids under spotlight

Many young South African athletes are taking sports supplements despite the fact that there is limited evidence to support the efficacy and safety of most of these substances.

0

Winning is the ultimate goal for athletes. To achieve their aim, sportsmen and women often look beyond the tried and tested methods of well-planned training programmes, adequate rest, and a balanced diet, searching for a magical elixir – the ultimate nutritional supplement.

Athletes easily influenced

The anti-doping rules of the South African Institute for Drug-free Sport (SAIDS) are very clear: It is each athlete’s personal responsibility to ensure that no prohibited substance enters their body. Yet the misguided use of nutritional supplements among school-aged athletes is on the rise in South Africa.

A research study shows that more than half of teenage rugby players in a KZN admitted to using a nutritional supplement 3–4 times a week. In another study, under-16 rugby players were interviewed, and 42% reported using at least one supplement, with over 60% of these rugby players believing the supplements to be safe.

Read: Makers of nutritional supplements face charges

Young athletes are easily influenced by aggressive marketing by sports supplementation companies, despite the fact that there is limited evidence to support the efficacy and safety of most of the sports supplements on the market. Below is a summary of the claims and scientific evidence of some of the most prevalent sports supplements used by South African youth.

Protein

Out of all supplements, the use of protein powders is the most prevalent. According to research almost seven out of 10 young sport participants reported using a protein supplement to gain muscle, and four out of 10 believe that the protein quality in supplements is higher than the protein from food sources.  

Protein is involved in muscle gain, which makes it an attractive supplement for young athletes trying to bulk up. Currently there are no studies supporting the belief that protein from supplements (e.g. whey protein) is superior in building muscle compared to the protein as found in food sources.

There is also no evidence supporting that excessive amounts of protein are needed to build muscle mass as claimed by the manufacturers, media, coaches, and trainers. Young athletes should rather focus on consuming an adequate amount of energy from carbohydrates, protein, and fats for optimal performance and growth.

Although a certain amount of protein is required for optimal muscle growth and development, excessive amounts of protein consumption will be excreted as amino acids in the urine.

Read: Protein and sports performance

That said, for many active young athletes with busy schedules, the convenience of whey protein shakes to help meet protein needs cannot be overlooked. It is recommended that young athletes consult with a registered dietitian who can assess if additional protein intake is in fact necessary and advise on preferred food-based measures to consume more protein, such as including milk, eggs, lean meat, chicken and fish in the diet.

Creatine

Creatine (usually in the form of creatine monohydrate) is a nitrogen-containing compound made by the liver and kidneys. You can also consume dietary creatine in the form of protein-rich sources such as meat, chicken and fish. Although the typical Western diet provides more than sufficient protein to meet the body’s creatine requirement, creatine supplements are some of the most popular among young athletes.

The claims supporting creatine supplementation centre around the fact that creatine is stored in the muscle as phosphocreatine, a substrate which helps generate energy at high intensity exercise. Creatine is therefore marketed to sportsmen and women who need quick, repetitive, high intensity efforts with brief recovery, as in power sports.

Read: Creatine

Creatine is also used to gain body mass. When supplementing high doses of creatine, it is stored in the muscle with water, hence the weight gain is partly from water. This also means that the training athlete can do more repetitions during training, gaining the desired muscle mass.

Numerous studies have supported the claims that creatine supplementation increases muscle gains when training. But while there is evidence of creatine’s efficacy in adults (following specific creatine loading protocols), in young athletes the potential risks far outweigh any benefit.

There is some concern about overuse with side effects such as nausea, vomiting, diarrhoea, dehydration, and muscle cramps and tears. Accordingly, creatine supplements should not to be used by children under 18 years due to the potential unknown adverse side effects, as advised by the American College of Sports Medicine (ACSM) and supported by SAIDS.

BCAA

The branch chain amino acids (BCAAs) are leucine, isoleucine, and valine and can be found in foods such as meat, chicken, fish, milk, and legumes. It is suggested that BCAAs can act as a fuel source during exercise by sparing glycogen.

Glycogen is the storage form of glucose, stored in the muscle and liver and is the primary energy source during exercise. Oral BCAA supplementation is also claimed to prevent muscle breakdown and accelerate the repair of muscle damaged during exercise.

Read: What does blood sugar level mean?

The International Society for Sports Nutrition (ISSN) found that these claims for BCAAs are supported by research and classifies BCAAs as a supplement that is possibly effective for enhancing performance. However, more research is needed as these recommendations are based on adult studies and aren’t necessarily relevant to young athletes

Fat burners

It is appealing to think that a nutritional supplement has the capacity to burn fat. Several fat burning nutritional supplements are marketed, claiming to support athletes’ weight loss goals by suppressing the appetite or stimulating fat burning. Most weight loss supplements are herbal extracts and metabolites (molecules that are the products of the body’s metabolism).

According to the ISSN, for most of the fat burners there is only weak evidence that they have any effect on fat metabolism. The following supplements are apparently ineffective for fat burning: L-carnitine, chromium, CLA (conjugated linoleic acid), guarana, ginseng, and Garcinia Cambogia (hydroxycitric acid or HCA).

Among these supplements, ephedrine/ephedra is the poster child for weight loss. Ephedrine is found in an herbal stimulant called ma huang, banned by the Food and Drug Administration (FDA) and World Anti-Doping Authority (WADA).

A modest weight loss of 0.9kg per month in comparison to a placebo was shown in some clinical trials, but the side effects of taking this stimulant include great health risks, more than the benefits are worth. These risks are: high blood pressure, stroke, heart attack, kidney damage, seizures, psychoses, and even death.

Read: Weight-loss myths abound

There are claims to support that caffeine can stimulate lipolysis, which is the process of fat breakdown in the body’s fat cells. While caffeine may play a very small role in weight loss, independent of a kilojoule-controlled diet, it is so insignificant that it does not justify drinking more coffee.

The same argument applies to drinking more green tea. Green tea is rich in a polyphenol called EGCG (epigallocatechin gallate), which may increase fat burning. Studies on the efficacy of green tea are limited as evidence shows that any potential for weight loss is not because of the catechins but because of the caffeine in green tea, either alone or in combination with the catechins.

If green tea is effective for weight loss, the safest way would be to consume a cup or two each day as part of a kilojoule-controlled healthy diet. Ultimately, the most effective way to lower your body fat percentage is through a kilojoule-controlled diet in combination with an effective and well-balanced training programme.

Proceed with caution

Young athletes, parents and coaches are cautioned to consider the lack of legislation and control in the supplement industry. Products are marketed with misleading and unproven claims, incorrect labelling, and an unfortunate lack of evidence-based efficacy and safety. Below is a concise summary from the ISSN which ranks sports supplements (rather than brands) into four categories based on available scientific evidence.

Table: Summary of categorisation of dietary supplements based on available literature.

(Source: Kreider et al, 2010.)

table

Food first, supplements second

As sports nutritionist and 21-time Iron Man, Professor Asker Jeukendrup, says, “A proper diet cannot make an average athlete elite, but a poor diet can make an elite athlete average.” Young athletes should ultimately rely on a nutritionally balanced diet made up of real food rather than relying on the unproven proposed nutritional power of synthetic sports supplements.

It’s concerning to note that only 2% of young athletes obtain their nutrition information from the professionals, i.e. registered dietitians. A registered dietitian with an interest in sports nutrition should be consulted as a valued resource for young athletes to reach their ultimate performance and sporting potential.

To find a registered dietitian in your area, go to http://www.adsa.org.za/Public/FindARegisteredDietitian.aspx

Read more:

Recommendations on supplements

Supplements affect kids' brains

Steroids in dietary supplements?


References:

- Claasen A. Position Statement of the South African Institute of Drug Free Sport (SAIDS) on the use of supplements in sport in school-going youth. 2011.
- Duvenage KM, Meltzer ST, Chantler SA. Initial investigation of nutrition and supplement use, knowledge and attitudes of under-16 rugby players in South Africa. South African Journal of Sports Medicine. 2015;27(3):67-71.
- Jeukendrup A. Sports nutrition: from lab to kitchen. 2nd edition. 2012. Meyer and Meyer Sport. United Kingdom.
- Joint Position Statement by the American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada. Nutrition and Athletic Performance. Journal of the American Dietetic Association. 2009; 509-526.
- Kreider et al. ISSN exercise & sport nutrition review: research & recommendations. Journal of the International Society of Sports Nutrition 2010, 7:7-1-43.
- Nemet D, Eliakim A. Paediatric sports nutrition: an update. Curr Opin Clin Nutr Metab Care. 2009;12:304-309.
- Stegen B. Determining the general- and sports-related nutrition knowledge of male adolescent rugby union players attending a secondary, urban government boy’s school in Pietermaritzburg, Kwazulu-Natal. 2014. Unpublished.
- Williams MH, Anderson DE, Rawson ES. Nutrition for health, fitness and sport. 10th edition. 2010. McGraw-Hill, New York.

The dietitians from Nutritional Solutions are Health24's expert team of registered dietitians.

 
advertisement