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Race Fueling

Triathlon Nutrition: Concerns About Supplements

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Pip Taylor is a professional triathlete and sports nutritionist.

Written by: Pip Taylor

Professional triathlete and sports nutritionist Pip Taylor provides advice on incorporating supplements into your overall nutrition plan.

Before taking any supplements, you should have a good reason for doing so that is based more on scientific and medical evidence than on what your friend or training partner is doing. Talking to your doctor and/or nutritionist is a good place to start in addition to perhaps undergoing a blood test a couple of times a year. This is really the only way to see if you are actually deficient in any key nutrients.

Taking supplements “just in case” or taking multiple supplements can easily result in potentially dangerous overdoses of various minerals and vitamins at levels that can be toxic or have unpleasant side effects. In fact, in most cases, over-supplementing creates a far greater problem than being slightly deficient. Further adding to the need to speak to a qualified healthcare provider is the possible interaction of supplements and herbal products with  any medications you may already take.

If you have identified a deficiency, then first take a look at your diet. Eating a wide variety of fresh, wholesome foods should be the first and foremost way that you obtain everything you need. If this has been addressed and there are still gaps (which is entirely possible, especially when under the high physical stress of training hard for a triathlon), you might decide to supplement. When you do this, only take supplements in the recommended dose—more is not always better! Proper dosage may vary based on gender, body size, physical activity level and a number of other factors. This caution also applies to any herbal medicines or supplements: Overdosing can be toxic, even with natural herbs.

The FDA does not regulate nutritional supplements, so bear in mind that by using the product, you are trusting the manufacturer that what is written on the label is actually in the supplement, that the dosage written on the bottle is correct and that it is completely pure. Supplements, medicines, steroids, etc., are often all made in the same manufacturing plants, so you are also relying on the company’s manufacturing practices. Cross-contamination is a major concern for elite and professional athletes who undergo drug testing, as they cannot always be completely assured of what they are taking yet are still responsible for what is in their bodies. However, it should be a concern for everyone, as you should know exactly what you are putting in your body. Choose reputable brands, even if it means spending more, as you are more likely to get what you pay for. Be aware of any claims made that are not supported by scientific studies published in reputable journals, and remember that there is a difference between biochemical differences seen after supplementation and functional or performance benefits that many studies simply assume.

Getting back to the specifics of your question, I’ll explain the potential and/or claimed benefits of the supplements you mention:

Flax and fish oils are good sources of omega-3 fatty acids that are essential nutrients and play important roles in many bodily functions. It can be difficult for many get sufficient adequate levels of these fatty acids from the diet alone, so this supplement may well be warranted for general health and athletic performance and is backed by plenty of credible research.

Rhodiola rosea and cordyceps are both herbal supplements with big claims of improving well-being by reducing fatigue and pain. Rhodiola is said to stimulate the nervous system and cordyceps is believed to facilitate the delivery of oxygen to muscles. However, to date there is little unbiased scientific research examining the safety and efficacy of these supplements, so more research is needed, particularly on trained athletes.

Beta-Alanine is a non-essential amino acid and the precursor to carnosine, which aids in reducing fatigue. Some studies suggest that it may improve strength and power in short anaerobic sprints or lifts by increasing muscle carnosine levels and delaying the point of fatigue. Again, though, well-designed studies on highly trained athletes have produced equivocal results, so further research is warranted.

L-glutamine plays an important role in protein metabolism and immune cell function. It is the most abundant amino acid in skeletal muscle and can become somewhat depleted under hard training conditions. Food sources include fish, chicken and eggs as well as some types of recovery drinks (e.g. Endurox R4). L-arginine is a conditionally essential amino acid—that is, the body normally produces sufficient quantities of it on its own but may require an outside source under stressful conditions. It is found in foods such as nuts, seeds, grains and meats. It is important for many bodily functions, but unless you have a medical condition or you are on a restricted or poor diet it is unlikely that you would be deficient.

Creatine monohydrate has been shown to boost strength and power and aids muscle growth. It is more commonly used by athletes in explosive and power-based sports. With creatine supplementation, muscle weight gain is typical (along with water retention), resulting in an increased body mass, which is not necessarily what most triathletes are aiming for. Also, as is the case for many supplements, consequences of long-term use are not yet known.

The bottom line on supplements is that they can work and do have their place in promoting health and athletic performance. However, they should not be taken blindly. Seek professional advice about what will work for you.

Pip Taylor is a professional triathlete and sports nutritionist. She has raced professionally around the globe for nearly 10 years. For more information, visit