By Nora, Leah, Justin & Taylor

INTRODUCTION  Many athletes use dietary supplements as part of their regular training or competition routine, including about 85% of elite track and field athletes.  Supplements include vitamins, minerals, protein, amino acids, creatine, carnitine and caffeine.  Often used without a full understanding of the potential benefits and risks associated with their use.  Are they necessary for athletes? What are the risks?

VITAMINS & MINERALS  Many athletes take nutritional supplements in doses up to 1000 times the Dietary Reference Intakes.  In general, vitamin and mineral supplements have not been proven to improve training or performance.  Negative Side-effects:  Illness  Tissue damage  Vitamins can be toxic when taken in excess

 Over 90% of vitamin supplements on sale are synthetic.  Nutritionists recommend food first because it provides a wide variety of vitamins and minerals and other dietary factors that are not found in supplements.  The body is better at breaking down these natural foods than synthetic supplements.  Supplements can be beneficial only when the athlete has a clear deficiency  Pregnant women  Adults over 50  Vegetarians

PROTEIN AND AMINO ACID SUPPLEMENTS  Protein and amino acids are an essential component of any balanced diet  Supplements used to increase muscle mass, strength and endurance  Some studies show that amino acids enhance the growth hormone insulin  Too much protein can cause your body to have toxic effects due to too much urea, which leads to loss of water  This dehydration can cause cramps and decrease your abilities in sport.

ARE AMINO ACID SUPPLEMENTS EFFECTIVE?

CREATINE  Used for short-term, high-intensity exercise.  Found in skeletal muscle and is where the rapid production of ATP takes place, which provides immediate energy.  When phosphocreatine stores are depleted, creatine supplements are taken to refill and increase the content in skeletal muscle.  Consuming carbohydrates can increase the uptake of creatine by more than 50%.

 Creatine does not improve the bodies maximum force, it allows the body to maintain a high-intensity exercise longer.  There is a limit that can be reached and the excess is excreted from the body.  Improvement is only obvious during sprint exercises during running, swimming, and cycling.

CARNITINE  Synthesized in the kidneys and liver and stored in skeletal and cardiac muscles.  Found in living cells that is used to transport fatty acids to the mitochondria during the breakdown of lipids for the generation of metabolic energy.

CARNITINE CONT’D  Theorized to be a super fat burning substance but that has never been proven  Carnitine supposedly decreases lactate production, delays fatigue, increases VO2, spares glycogen, and induces the loss of body fat.  Carnitine deficiency is not a concern for athletes as adequate levels remain in muscle tissues during exercise.

CARNITINE’S IMPORTANCE Carnitine is important for the muscle because it:  Improves the efficiency or production of ATP with oxygen  Reduces the need for anaerobic glycolysis  Can result in a 44% reduction of Lactate production.

CAFFEINE PROS  Can increase performance during prolonged endurance and short-term intense exercise  Increases alertness and reduces fatigue CONS Urinary caffeine limit: more than 3 cups of coffee before a competition  Potential diuretic effect which could cause dehydration, nervousness and irritability  Can enable athletes to go beyond safe physiological limits by delaying fatigue  Risk of drug dependency

DO ATHLETES NEED SUPPLEMENTS?

QUESTIONS?

REFERENCES Need-a-Supplement-.aspx Hoax_UCM_432104_Article.jsp# performances/