“Boosts stamina, endurance and strength. Clinically proven to burn fat faster. Will speed up your metabolism. Can increase your muscles’ energy-loading system and propensity for sustained power and performance.”
Sounds too good to be true?
Unfortunately for athletes, scientific research into the effects of dietary supplements has thus far proven inconclusive, regardless of what their manufacturers want you to believe. Why, then, do ever-hopeful runners dash to their local chemist and health food store eager to spend their hard-earned cash on products whose unsubstantiated claims fail to guarantee to ‘boost, improve or increase’ anything, except the burgeoning profits of supplement companies? Perhaps to find the elusive key – yet to be discovered – to improved athletic performance, neatly packaged and easily taken in capsule or tablet form.
In the mid-1990s, brilliant claims on supplement labels prompted scientists to study the promotional claims of several popular dietary supplements on the market which target athletes. Their results, which appeared in the Annals of Pharmacotherapy, prove startling: no published scientific evidence supports the promotional claims of a large number of dietary supplements.
In the March 1998 issue of The Physician and Sports Medicine, researchers claim that, although certain particular medical conditions may warrant vitamin and mineral supplementation, studies into the alleged benefits of these supplements have revealed no benefits in athletic performance that cannot be achieved by an adequate and balanced diet alone. Further research echoes similar sentiments.
Attempting to negotiate the murky waters of supplements is Anita Bean, author of The Complete Guide to Sports Nutrition. Bean – along with the British Nutrition Foundation – believes vitamins are needed in very small amounts for many bodily processes, including energy production and exercise performance.
Most vitamins cannot be made in the body and must therefore be supplied through our diet. Likewise, minerals have many regulatory roles in the body and are largely obtained through diet. Although everyone has different nutritional requirements, the Committee on Medical Aspects of Food Policy (COMA) in the UK has set estimated standards called Dietary Reference Values (DRVs) – formerly known as Recommended Daily Amounts (RDAs) – to guide the consumer.
That said, Bean concedes: “It is conceivable that regular, intense exercise can increase the requirement for a number of vitamins and minerals, especially those involved in energy production.” Studies reveal that vitamin and mineral deficiencies lead to poor performances. When corrected, performance improves. However, this still doesn’t mean that supplements themselves always improve performance.
While most scientific research does not support the intake of dietary supplements as being a factor in athletic prowess, other studies reveal that those who follow performance-enhancing or restricted diets, or who want to ensure proper dietary intakes, may choose a multivitamin or mineral supplement to help safeguard their diet. This is good news if you’ve ever been tempted to incorporate nutritional supplements along with your diet and training.
In a 1991 article in the International Journal of Sport Nutrition, scientists found that vitamin and mineral deficiencies are not very common among athletes, except in those who restrict their food intake in order to maintain body weight. When the diet is deficient, vitamin supplements may improve performance, but they’re not likely to have any effect if dietary intake is adequate.
According to a 1996 article in the New Zealand Journal of Sports Medicine, antioxidant vitamin supplementation can be recommended to individuals performing regular heavy exercise. Furthermore, in the Journal of Sports Sciences, researchers claim female athletes with infrequent or irregular menstruation may benefit from supplementary calcium to help preserve bone density.
Also making a persuasive case for dietary supplementation is Frederick C Hatfield, author of Ultimate Sports Nutrition: A Scientific Approach to Peak Athletic Performance. He reports that the real value of supplements isn’t their ability to produce instant performance results; rather, their benefits become evident after taking them daily over the course of several months. Because athletes use more energy than sedentary folk, their nutritional demands are higher. Therefore, Hatfield argues, “nutritional supplements usually, but not always, are necessary” to meet the increased demand. He suggests we should exceed our daily requirements by a safe margin to ensure we’re getting enough of what we need.
Hatfield faults scientific research that rejects the benefits of supplementation, claiming that most studies overlook a comprehensive nutritional approach and focus strictly on one or two vitamins or minerals at a time, separate from a total package. He says compelling evidence not only proves nutritional supplementation is beneficial, but that it is necessary for peak performance.
Where does all of this leave you, besides dazed and confused? Evidence on both sides of the fence seems terribly convincing. If you’re eating a balanced diet full of complex carbohydrates – fruits, vegetables and quality protein – most experts agree that nutritional supplements won’t improve your health, let alone boost your endurance, burn fat faster or speed up your metabolism. You’re probably meeting all of your vitamin and mineral needs through diet alone. Congratulations.
However, if you’re convinced you need a supplement to meet your nutritional needs, since your diet is less than perfect, the alphabet soup of dietary supplements presents you with bewildering choices. Shelves bulge with options. Here’s what you’ll find in your local chemist and health food shop right now. (Just don’t expect to find that ‘magic’ pill or potion that will transform you from a 10-minute miler into a world-class marathon runner overnight.)
Be sure to visit the cashpoint or bring along your credit card before venturing to your local chemist or health food shop in search of supplements: nutritional security doesn’t come cheap.
Although prices vary significantly depending upon the type and quantity of supplement, you should expect to spend at least £5.99 for one month’s supply of a multivitamin geared toward ‘sports-minded’ or ‘active’ people.
More specialist supplements can set you back double – if not triple – this amount, so proceed to the checkout queue with caution.
Remember, the British Nutrition Foundation warns that nutritional supplements are no substitute for a varied, balanced diet. The foundation also reminds consumers not to exceed the manufacturer’s guidelines for dosage, since some vitamins and minerals are toxic at certain high levels.
The DetailsFrom Vitamin A to zinc, we've divided all you need to know as a runner into three tables:
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