dr gary slater - supplement use in sports - ongoing controversies
DESCRIPTION
TRANSCRIPT
Sports Supplements…
Current Controversies
Gary Slater PhD APD Adv. ASD
Senior Lecturer (Masters of Sports Nutrition) University of the Sunshine Coast
National Performance Nutrition Coordinator ARU
Session Overview
• The current environment
• Product formulation…
– Evidence based vs marketing hype
• Inadvertent doping risk
• A help or hindrance…
– Could supplement use be impairing training
Sports Supplements
• 88% using supplements
• ‘Polysupplementation’ common
Dascombe et al. Int J Sport Nutr Exerc Metab. 13:274-280, 2010.
Majority of athletes did NOT know… •Supplement active ingredients (62%)
•Mechanism of action (57%)
•Potential side effects (57%)
•Recommended dosage (54%)
Dascombe et al. Int J Sport Nutr Exerc Metab. 13:274-280, 2010.
Dascombe et al. Int J Sport Nutr Exerc Metab. 13:274-280, 2010.
Majority of athletes used supplements for… •Health benefits
•Ergogenic potential
•On peer recommendations
Within commercial gyms… •Supplement use remains very common (85%)
•Supplementation practices vary by age & training objectives
Goston et al. Nutr. 26:604-611, 2010.
Goston et al. Nutr. 26:604-611, 2010.
Within commercial gyms… •Info primarily from readily accessible sources such as magazines
& other media, friends, health food store
• Athletes seek supplement information from readily accessible sources… – Magazines, on-line
– Fellow athletes, coaches
• Leaves athlete vulnerable to… – Ineffective protocols
– Doping
– Health implications
FitzSimmons & Kidner. J Accid Emerg Med. 15:196-197, 1998. Giampreti et al. Clin Toxicol. 47:827-829, 2009.
Prosser et al. Hum & Exper Toxicol. 28:259-262, 2009. Cons Rep. 75:24-27, 2010.
Session Overview
• The current environment
• Product formulation…
– Evidence based vs marketing hype
• Inadvertent doping risk
• A help or hindrance…
– Could supplement use be impairing training
‘Boron supplementation markedly elevated the
serum concentrations of estradiol & testosterone…’
Nielsen et al. FASEB. 1:394-397, 1987.
Session Overview
• The current environment
• Product formulation…
– Evidence based vs marketing hype
• Inadvertent doping risk
• A help or hindrance…
– Could supplement use be impairing training
Geyer et al. Int J Sports Med. 25:124-9, 2004.
Geyer et al. Int J Sports Med. 25:124-9, 2004.
Supplements & Doping
• Risks associated with supplement use are very real
• Athletes now have access to a much wider array of products domestically & internationally
• Athletes & coaches require global understanding of supplement regulation – Standards controlling labeling laws differ between countries.
In the USA, legislation allows supplement manufacturers to…
• Make claims regarding the effect of a product on the structure/ function of the body, as long as they do not claim to ‘diagnose, mitigate, treat, cure or prevent’ a specific disease
• Make claims for enhanced performance – be they valid or not
Supplements & Doping
• WADA Statement on nutritional supplements… – The ingestion of nutritional supplements pose a
special risk as they may contain or be contaminated with substances that are specifically banned
– As long as the production & sale of such supplements cannot be impeded & their purity cannot be guaranteed, the risk of testing positive in a doping test must be borne by the consumer
– ‘It was reaffirmed that the principle of an athlete’s strict liability for all substances found in his or her system needs to be maintained to protect the integrity of sport & the doping control process’
Session Overview
• The current environment
• Product formulation…
– Evidence based vs marketing hype
• Inadvertent doping risk
• A help or hindrance…
– Could supplement use be impairing training
Gomez-Cabrera et al. Am J Clin Nutr. 87:142-9, 2008.
Vitamin C supplementation
decreases training efficiency because
it prevents some cellular adaptations
to exercise
Gomez-Cabrera et al. Am J Clin Nutr. 87:142-9, 2008.
These results suggest that inhibition
of ROS attenuates some skeletal
muscle cell signalling pathways and
gene expression involved in
adaptations to exercise.
Petersen et al. Acta Physiol. 204:382-92, 2012.
Based on the contradictory evidence regarding the
effects of higher intakes of vitamin C and/or E on
exercise performance and redox homeostasis, a
permanent intake of non-physiological dosages of
vitamin C and/or E cannot be recommended to
healthy, exercising individuals.
Nikolaidis et al. Oxidat Med Cell Long. 2012.
…loading the cell with high doses of
antioxidants leads to a blunting of
the positive effects of exercise
Training…. We recommend that an
adequate intake of vitamins and
minerals through a varied and
balanced diet remains the best
approach…
Athletes should be cautioned about
taking Vitamin C chronically,
however, blackcurrant juice may
improve performance in the elite
Braakhuis et al. Eor J Sports Sci. 2013.
Athletes should be cautioned about
taking Vitamin C chronically,
however, blackcurrant juice may
improve performance in the elite
Braakhuis et al. Eor J Sports Sci. 2013.
Sports Supplements
• Athletes now have access to a much wider array of products domestically & internationally – Require global understanding of supplement regulation
• Engage significant others in education process • Consider establishment of supplement policy
– Base guidance on evidence based practice – Package & promote your system
• Recommendations may vary depending on athlete & resources available, specific goals, dietary intake etc.
• Be prescriptive…What, When, How much & Monitor
• Remain well informed – Talk with athletes – Visit supplement stores – Read both scientific & lay articles
