Athlete Dietary Supplements Quiz

Introduction

• Dietary supplements (DS) are widely used in sports.
• UK Sport, IOC, and WADA advise against DS due to risks.
• Sports authorities recommend a good diet before considering supplements.
• USOC also recommends that supplements should only be used alongside a good diet, and only if the diet cannot be modified.

What are Dietary Supplements?

• Oxford English Dictionary defines a supplement as "something added to supply a deficiency."
• FDA defines a dietary supplement as a product (excluding tobacco) that is intended to supplement the diet and contains ingredients like vitamins, minerals, herbs, botanicals, amino acids, dietary substances, concentrates, metabolites, constituents, extracts, or a combination of these.

European Food Safety Authority (EFSA)

• Supplements can be used to correct nutritional deficiencies or meet adequate nutrient intake.
• Excessive intake of vitamins and minerals can be harmful and cause side effects.
• Maximum levels are needed for safe use of food supplements.

Legislation and Labeling

• European Commission has set harmonized rules to ensure the safety and proper labeling of food supplements.
• Legislation regarding supplements differs across countries.

Prevalence of Dietary Supplement Use

• Supplement use varies across different types of athletes and backgrounds.
• Strength exercise and power sports have high supplement use.
• Supplement use varies among different countries. Prevalence percentages are listed in a table on slide 8

Common Sports Nutrition Supplements (from studies conducted in UK)

• In 1994, the most popular DS were multivitamins, followed by vitamin C, iron, and B vitamins.
• Recent UK studies indicate that multivitamins are still the most common supplement, followed by vitamin C, creatine, whey protein, echinacea, iron, caffeine, magnesium, and ginseng. Specific percentile values are listed on slide 10

DS Usage Patterns

• Usage patterns vary by country, athletic level, and sport.
• Some sports foods (e.g., carbohydrate/electrolyte sports drinks) are common and not always considered supplements.
• Recording of supplement usage can be inconsistent.

Reasons for Dietary Supplement Use

• Prevent/treat perceived nutrient deficiency, due to increased training demands
• Convenient nutrient source, particularly for training needs
• Direct ergogenic (performance-enhancing) effect
• Belief that top athletes are using the supplement

Efficacy of Dietary Supplements

• Level 1: Anecdotal evidence and expert opinion, common in the marketplace, commonly promoted by high-profile athletes.
• Level 2: Case series or observational studies, less common.
• Level 3: Randomized controlled trials, most common type of supplement research. Suitable quality research is essential.
• Level 4: Systematic reviews and meta-analyses. The highest level of evidence available, but rare, especially for new supplements.

Classification of Dietary Supplements (APRID Framework)

• APRID framework classifies supplements based on the quality and consistency of the evidence for their use.
  • A (Acceptable): Supplements backed by strong evidence (level 4).
  • P (Physiological): Supplements with a clear physiological basis, but limited research (level 2 and 3).
  • R (Research): Supplements with some evidence, but the evidence is not strong or conclusive (level 1 and 2).
  • I (Ineffective): Supplements with no clear rationale for use.
  • D (Disallowed): Supplements banned by WADA or deemed high risk.

'Acceptable' Category

• Considered safe for consumption.
• Practitioners can freely prescribe these supplements.

Sports Foods

• Carbohydrate drinks, powders, gels, and bars provide energy and glycogen resynthesis.
• Carbohydrate/electrolyte sports drinks provide energy and electrolytes.
• Carbohydrate and protein 'recovery' drinks, powders, and bars support post-exercise recovery.
• Electrolyte replacements provide electrolytes and support recovery. Protein powders also support protein supply
• Liquid meal supplements offer vital nutrients and additional energy.

Performance Supplements

• Supplements and their associated performance uses and physiological rationale are documented
• Caffeine: Improves alertness, enhances CNS effects as well as exogenous carbohydrate use and higher fat oxidation
• Creatine: increases muscle creatine stores, enables maintenance of greater training load

Performance Supplements Usage

• Sodium bicarbonate: increases hydrogen ion diffusion, improves performance during short, high-intensity exercise. Improves performance by combating lactic acid and acid-base balance
• Sodium citrate: acts as a buffer, similar to sodium bicarbonate.

Caffeine Supplement Background

• 90% of adults consume caffeine daily.
• Caffeine use was banned in urine tests between 1980-2003, levels above 12 mg/L.
• WADA removed caffeine from banned list in 2004.

Creatine

• Creatine is a naturally occurring compound derived from three amino acids.
• Non-vegetarian diets typically provide 1-2g of creatine daily.
• Supplements are available as Creatine monohydrate.
• Supplements can increase muscle creatine and phosphocreatine stores by approximately 20%.
• Loading doses (20g/day for 4-5 days) followed by maintenance doses (2-3g/day), or maintain at a steady level of 2-3g/day are strategies for maximizing creatine levels. Creatine is effective at maximizing levels, but it takes about 4 weeks to return to resting levels after this is done. Maintenance doses will keep levels elevated after this point

Creatine Use in Training Programs

• Creatine can be utilized in resistance training, interval and sprint work, and team/field/court sports involving intermittent work patterns.
• Creatine supplementation mechanisms include metabolic enhancements, molecular adaptations, and reduced muscle damage.
• Creatine does not increase skeletal muscle protein synthesis.
• Creatine does not appear to have any detrimental effects on plasma urea or liver enzyme activity.
• Supplementation is generally advised against in people with existing renal conditions, diabetes or hypertension.

Sodium Bicarbonate

• Used to enhance athletic performance. A common use of sodium bicarbonate is an antacid.
• Acute doses prior to short-duration, high-intensity sports can improve performance, resisting fatigue caused by acid-base imbalances
• Research shows improved performance has been shown in several events like 400m-800m running, 200m freestyle swimming, and team/court/field based games (particularly racket sports)
• Sodium bicarbonate has no apparent effect on performance during prolonged exercise with lower intensity
• Ingesting sodium bicarbonate increases blood bicarbonate concentration, leading to hydrogen ion removal and delaying fatigue. It also increases plasma lactate levels and overall is frequently associated with bloating, nausea and diarrhea

Sodium Citrate

• A buffer, with a similar use pattern to sodium bicarbonate, but with research showing a reduced risk of gastrointestinal distress.
• Typical dosing protocols are in the mg/kg range for 1-2 hours prior to exercise.
• Buffered agents are often consumed alongside a large volume of fluid containing carbohydrate to reduce issues associated with osmotic diarrhea. Citrate has a benefit over bicarbonate due to its ability to reduce this.

Health Supplements

• Multivitamins and multiminerals are included in health supplements
• No conclusive evidence that they enhance performance.
• Supplements may be important to individuals with restricted diets.
• Fish oils can improve metabolic function. Important for preventative measures to address bronchial irritation and to improve asthma-like symptoms
• Antioxidants: animal research suggests that green tea can delay fatigue 8-10 weeks post-supplementation

Cardiovascular Effects

• Supplements that increase blood flow include l-arginine (precursor of l-citrulline), l-carnitine, nitrates, and various polyphenols.
• Oral l-arginine does not seem to increase vasodilation, but can have the benefit of reducing ammonia in the blood, which is important in recovery post-training.
• Citrulline may be more effective than l-arginine
• Blood flow enhancement does not demonstrably improve performance

Carnitine

• Synthesized from the amino acids lysine and methionine.
• There is limited evidence that carnitine supplementation increases fatty acid transport, and no evidence that this improves performance.

B-alanine and Carnosine

• Carnosine is a dipeptide of b-alanine and histidine.
• About 99% of carnosine stores are in skeletal muscle, with greater concentration in Type II muscle fibers.
• Daily doses of b-alanine, around 100mg/kg, increase muscle carnosine content by 60-80%.

Branched-Chain Amino Acids (BCAAs)

• BCAAs (leucine, isoleucine, valine) influence post-exercise protein synthesis.
• Leucine specifically regulates the protein kinase mTOR.
• BCAA supplementation doesn't seem to reduce muscle soreness after exercise.
• The recommended amount is 0.3-0.5 g/kg per hour or 2-4 g per hour, ingested repeatedly during exercise and recovery. Large does of up to ~30 g per day are well tolerated

Hydroxymethylbutyrate (HMB)

• HMB is a metabolite of leucine.
• It can enhance recovery by attenuating exercise-induced skeletal muscle damage.
• HMB should be taken close to the workout.
• Recommended to be used 2 weeks prior to exercise.
• Two main forms include Calcium HMB (HMB-Ca) and Free acid form of HMB (HMB-FA).

Central Nervous System Effects

• BCAAs increase tryptophan during exercise (which crosses the blood-brain barrier, resulting in fatigue)
• Phospholipids increase choline and may reduce fatigue.
• Tyrosine increases dopamine levels, potentially improving mood and cognitive function in cold exposure.

Health Supplements for Joint Health

• Antioxidants, fatty acids, vitamins B3, B5 and D, calcium, boron, proteolytic enzymes, glucosa-mine, chondroitin, methylsulphonylmethane, S-adenosyl methionine, type 2 collagen, hyaluronic acid and soy isoflavones are supplements related to joint health.
• Most of these supplements are ineffective

Colostrum

• Bovine colostrum is calf milk, containing higher concentrations of immune, growth and antimicrobial factors than regular milk.
• No significant effect on anaerobic performance.
• There is some evidence about improved high-intensity and post-exercise performance.
• Colostrum contains IGF-1, which is a banned substance by WADA.

Glucosamine

• Glucosamine (C6H13NO5): an amino sugar that's a primary building block of proteoglycans and marketed as treatment for osteoarthritis.
• Most supplements have approximately 90% gastrointestinal absorption.

Glutamine

• Glutamine is a widely abundant amino acid.
• It is used as a fuel in the immune system and can improve immune function after a strenuous workout.

Echinacea

• Echinacea is a genus of plant species (coneflower) and used as an immune-enhancing supplement.

Melatonin

• Melatonin affects circadian rhythms and biological functions.
• Supplements are available over the counter, but sale of hormone is illicit in some places.

Medium-Chain Triglycerides (MCTs)

• MCT supplements are easily absorbed and oxidized as fuel, preventing body fat deposition.
• MCTs are helpful for fuel during endurance and ultra-endurance activities, by sparing glycogen,
• High intakes of MCTs (>30g) are associated with gastrointestinal issues.

Risks and Benefits of Dietary Supplements

• Supplement use should be viewed cautiously due to potential fortification,
• Special consideration is needed for people with various medical conditions (e.g., low protein in diabetics, sodium restrictions in hypertension).
• There are potential contradictions of use for some conditions (e.g., caffeine).

Contamination, Fake or Doping

• Elite athletes are accountable for banned substances found in their systems.
• Dietary supplements often contain multiple different products (some of which may be banned), and are frequently mislabeled.
• Products may contain banned substances or be mislabeled, increasing the risk of a positive doping test.

Placebo Effect of Dietary Supplements

• A relationship between performance status and placebo response may exist.
• Athletes may believe products cause improvements / or conversely, decrease performance. The actual observed effects may differ under different conditions (i.e. if a substance is active vs inert vs manipulated expectation).

Test your knowledge about dietary supplements used by athletes. This quiz covers recommendations from UK Sport, the US Olympic Committee, and regulations from various health authorities. Explore definitions, risks, and popular trends in the world of athletic supplements.