WHAT DO WE KNOW ABOUT NUTRITIONAL SUPPLEMENTS?

Transcription

1 EWF Coaching & Scientific Seminar, Dublin, 7/8 Oct 2016 WHAT DO WE KNOW ABOUT NUTRITIONAL SUPPLEMENTS? Dr Mike Irani Chairman IWF Medical Committee and TUE Committee (IWF Drug Hearing Panel)

2 Distinction between: Supplement v Substitute In addition to. To replace.

3 Health v Improving Performance Subtle difference: Health improves performance, BUT improving performance may not improve health

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6 Numbers Literature Review Nutrition Doping Year

7 Literature Review Num ber Number Nutrition Doping Nutrition Year

8 For Example: Collagen hydrolysate: Milk-based protein + CHO: Joint pain in athletes (Clark et al, May 2008) Isokinetic muscle performance CK & myoglobin (Cockburn et al, Aug 2008)

9 Anti-oxidants: Multinutrients; recovery, injury time Atalay et al, June 2006) Vit E & Vit C: [Lactate] blood; V0 2 max Aguila et al, Sept 2007) No effect (Yfanti et al, July 2010)

10 More... HC0 3 Loading: Small (worthwhile) benefits Acute doses :? Use (Burke, March 2007) BCAA: Exercise induced muscle damage Muscle protein synthesis Immune regulation (Negro et al, Sept 2008) Beta-hydroxy-beta-methybutyrate (HMB): Minimal strength, lean body mass (untrained athletes & patients). Cannot be recommended. (Palisin, Aug 2005)

11 ... and of course: CREATINE! Most effective for short bouts of high-intensity physical activity No effect on force production Little evidence for isometric force production Little benefit for prevention of muscle damage or post-exercise soreness However performance in jumping, sprinting or cycling No adverse effects in short term use (Bemben. 2005)

12 Carnosine Found in twitch fibres Made from L-histidine and betaalanine* Evidence based improvement in performance Potential side effects? (Derave et al, March 2010)

13 ...not quite! No benefit to multiple sprint performance (Glaister, May 2006) Endurance (Reardon et al, Oct 2006)

14 ... Odd one: Quercetin Muscle oxidative capacity & endurance in mice No effect in man (Cureton, et al, Oct 2009)

15 Cocktails? Caffeine + creatine + HCO 3 : multiple-sprint performance Beta-alanine, colostrum: Weak evidence BCAA, HMB, ribose: No evidence (Kristiansen et al, April 2005)

16 Points to Note Training v Competition Isolated performance (e.g. single sprint) v team-sport (e.g. football) Long term effectiveness Adverse effects: short + long-term Combination/ high doses of substances Legality of substance (Bishop, Dec 2010) (Irani, May 2012)

17 Adverse Effects Overall few for intermittent, single use Anti-oxidants (Vit C/E) may affect inter-cellular signalling - muscle performance Vit E: all-cause mortality Creatine: renal stones + creatinine (McGinley et al, 2009)

18 Glutamine Useless in healthy humans Glucosamine May reduce post-exercise joint pain

19 Zinc Free radical production?effect on performance (Kara et al, Apr 2010)

20 Magnesium Free + total testosterone levels, especially in those who exercise (Cinar et al, Apr 2011) Maybe low in athletes diet (Czajan et al, 2011) Iron Not justified (Rodenberg, July 2007) Ginseng Cannot be recommended (Palisin, June 2006)

21 Carnitine No effect on exercise performance Spriet et al, 2008) Arginine No influence (Abel et al, June 2005)

22 L-Tryptophan Modified perception of fatigue (aerobic work) (Javierre, May 2010)

23 Protein & Amino Acid Supplements The use of these supplements for healthy, non-competitive adults engaged in recreational sport is usually not warranted (Nemet, Wolach, Eliakim. Isr Med Assoc J, May 2005)

24 So what have we learnt? CHO + caffeine helpful Protein only helps if CHO is low Iron if anaemic L-Tryptophan may reduce fatigue sensation?creatine (but large amounts) No evidence that other interventions help especially for weightlifting

25 REMEMBER! The most important message is to use a nutritional supplement only if it is deemed of benefit (and safe) by a nutritional expert (de Hon et al, Nov 2007)

26 Also REMEMBER It is essential that an evidence-based approach to the prescribing of medication and nutritional supplements is adopted to protect the athletes health and prevent them from testing positive in doping controls (Tscholl, Dvorak, Am J Sp Med, Jan 2010)

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28 THE NEW ERA OF DOPING: WHAT & WHY? Professor Mike Irani Dublin, 7/8 OCTOBER 2012

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34 How may we reduce positive doping tests? Education who teaches? Penalty does it work?

35 EDUCATION When is the best time? Who is the best teacher?

36 BEST TIME Age 11-17y Males > females Cohorts, not necessarily teams Positive relationship between supplements and anabolic steroid consumption Injury Threat to sponsorship

37 BEST TEACHER Who do they ask? Strength coach: 37% M; 20%F But overall: 71% Athletic trainers 60% Coaches 41% Physicians Also media: 79% Internet 68% Magazines 52% TV

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41 In Practice (Athens OG 2004) Doping Control Form; TUE application: 24.3% Declared use of medications or food supplements 45.3% Food Supplements; 43.2% Vitamins; 13.9% Protein/amino acids Especially power sports NSAIDs 11.1%; Analgesics 3.7%

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45 CANADIAN COMPETITORS USE OF SUPPLEMENTS & MEDICATION IN ATLANTA (1996) V SYDNEY (2000) Atlanta % Sydney % (257/271) (300/304) Dietary Supps Vitamins 59(M) 65(M) 66(F) 58(F) (Boxing 91) (Swimming 76) Minerals 16(M) 30(M) 45(F) 21(F) (Cyclists, iron 73)

46 Atlanta% Sydney% Nutritional 35(M) 43(M) Supps 43(F) 51(F) (cycling 100) (Creatine, amino acids) Medication (NSAID) (NSAID) (Soft Ball 60) (Gymnasts 100) (Huang et al, Jan 2006)

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48 THANK YOU