What is a supplement?
There is no single definition, either legal or within the nutritional science of what constitutes a dietary supplement. (Maughan et al 2018) (office of dietary supplements, national institute of health 1994)
In the journal of sports nutrition and exercise metabolism, the definition is food, food component, nutrient, or non-food compound that is purposefully ingested in addition to a consumed regular diet, with the aim of achieving specific health and/or performance benefit.
Supplements come in many forms.
- Functional foods, foods usually enriched with added nutrients.
- Formulated foods and sports food, protein bars, recovery bars.
- Single nutrients, Vitamins, minerals.
Although most athletes take supplements for the advantage of intended and claimed effects or benefits, a range of motives underpin supplement use. (Garthe and Maughan 2018)
These reasons include:
- To correct or prevent nutritional deficiencies.
- For extra energy and nutrients to help with exercise.
- To achieve a specific and direct performance benefit.
- To gain performance benefits from an accrued outcome, such as better recovery, more intensity in training, optimising mass and/or body composition.
- A financial gain such as sponsorship.
- A just in case.
- They know other competitors are taking them and worry they won’t be as good without.
How do we find out what works in this crazy world of pills and powders? We must look at the evidence provided in studies. However, we can’t just read any study and take it a face value. Most studies are completed by or in conjunction with the company selling the product. The studies we look at must meet a strict criterion, like some of the following points, so we know they are reliable. (Burke and Peeling 2018)
- There must be an amble sample size and appropriate participant characteristics.
- They must mimic, as close as possible the conditions they would be used in.
- Standardisation, the study should be repeatable.
- Use of protocol. (specific product, dose, timing)
- Independent verification of the contents of the supplement.
- A performance protocol that is valid, reliable, and repeatable.
- Interpretation of the results. Would they carry over into real-life sports?
There are other guidelines for supplements that are used to treat or prevent nutritional deficiencies, but we can look at them on a separate post later.
Supplements that have strong evidence for benefiting performance
- Caffeine, 3-6mg/kg of body weight, taken 60mins before exercise. Doses higher than this have been shown to have a detrimental effect.
- Creatine, this is the most studied supplement this past decade. 3-5g per day. There is a loading phase although not a lot of evidence to suggest this is any more beneficial.
- Nitrates, found in high nitrate foods, such as leafy greens. Ideally 2-3hrs before exercise. Prolonged periods of intake have also been shown to be beneficial.
- Beta-alanine, 65mg/kg body weight, or split doses throughout the day. More beneficial if taken for longer periods, 10-12 weeks in most studies.
- Sodium bicarbonate, 0.2-0.4g/kg bodyweight. Taken 60-150mins before exercise. 3-4 smaller doses over the day also beneficial and better for athletes that are affected by stomach upsets.
Supplements that aid Recovery
- Creatine monohydrate, reduced symptoms of, or enhanced recovery from, muscle-damaging exercise.
- Beta hydroxy beta methylbutyrate, studies show this is good for times of inactivity and recovery from injuries as can slow down the loss of muscle mass. It has no real benefit to strength or muscle mass.
- Vitamin D needs more research, but current studies show high levels May help protect against stress fracture, also it has been found important for the immune system.
- Protein can stimulate muscle mass gains but the effects aren’t large, can also promote lean mass retention and weight loss.
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Office of Dietary Supplements, National Institutes of Health. (1994). Dietary supplement health and education act of 1994. Retrieved from https://ods.od.nih.gov/About/DSHEA_Wording.aspxExport Citation
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