SPORT NUTRITION Week 12

What you need to know… When and why are CHO and protein important? How does a diet need to change for different sports? What should be eaten before, during and after exercise? What are the benefits of dietary strategies? –CHO loading, creatine, caffeine, hydration, minerals

Carbohydrate (CHO) Major fuel source –Extended, high intensity –Prolonged, sub-maximal Limited capacity to store Important to eat before, during and after exercise The more physical activity the more CHO required to be consumed

Protein Recovery and __________ of body tissue damaged during exercise Athletes __________ need extra protein in diet Normal diet provides sufficient protein

Preparing for Competition Specific nutritional strategies will help the athlete to reach optimal performance The athlete needs to avoid nutrition related fatigue –Depletion of __________ –Hypoglycemia (low blood glucose) –_____________ –Low blood sodium levels

Short Duration Sports Glycogen depletion does not normally occur Little need to increase __________ intake Important to restore glycogen levels in __________

Team Sports Slight increase in CHO intake in hours before competition can be beneficial

Prolonged, Sub-Maximal Events Examples: Increasing CHO intake is important to increase glycogen stores Should be done hours before competition

The Pre-Event Meal Goals of a pre-event meal –Finish topping up glycogen stores –Top up fluid levels –Prevent hunger Timing –__________ hours before event

The Pre-Event Meal What to eat –__________ GI foods Why? –Low in __________ Fluid – ml prior to event

During Exercise Events <60 mins –No intake needed, stored CHO and fat is adequate Team sports mins –CHO intake helps maintain blood glucose levels Endurance events >90 mins –Very important; ml of sports drink per hour Ultra endurance events >4 hrs –Solid food high in CHO –Small amounts of fat and protein

Recovery Restore __________ and liver glycogen levels quickly High GI foods within __________ mins of activity

Dietary Strategies Carbohydrate loading Creatine supplementation Caffeine Hydration considerations Minerals

Carbohydrate Loading Benefit for athletes exercising for 90+ mins Increases muscle glycogen levels –Exercise at optimal pace for longer Exercise tapers off and carbohydrates are increased Prolongs CHO as main fuel and delays reliance on fats May increase in __________ due to extra muscle glycogen and water

Creatine Supplementation Hope to increase power, strength and anaerobic performances Powder ingested daily for 5-7 days Increase in rate of PC resynthesis during recovery between bouts of high intensity activity –Eg: interval sprint training –Better able to use __________ system to provide energy before using lactic acid system

Creatine Supplementation Possible side effects –Weight gain due to increase in water retention –Muscle cramps, dehydration –Seizures, diarrhoea, anxiety Only to be considered after consulting a dietitian or nutrionist

Caffeine Benefits –Glycogen sparing for endurance athletes –Stimulates CNS, which can alter perception of fatigue and effort –Stimulates release and action of adrenaline –Diuretic (promotes fluid loss) Who would use it?

Caffeine Side effects –Diuretic: fluid loss = dehydration and impact on temperature regulation –Insomnia –Elevated blood pressure Where from? Doping controls? –Yes, allows normal ‘social’ consumption

Hydration Considerations Water alone is not the most efficient way to rehydrate –It causes bloating, reduces thirst, increase urine output Fluid lost when exercising contains mineral salts (__________) that need to be replaced Sports drinks are used because they contain electrolytes and carbohydrates

Hydration Considerations Hypotonic Low electrolytes and CHO levels Absorbed quickly Suitable for athletes who need fluid, without CHO Isotonic Similar amounts of electrolytes and CHO that the body requires Absorbed quickly Preferred by athlete for refuelling and rehydrating Hypertonic Very concentrated with CHO Slower absorption Usually after exercise to replace glycogen

Minerals Often minerals supplements are taken –Iron, calcium, magnesium, potassium, sodium, zinc, phosphorus However, a healthy balanced diet contains enough minerals Eg: Iron –Increases oxygen carrying capacity of RBC –Hence, improved __________ capacity

Activities Read p and complete activity 9 (p.119) Go to u/ais/nutrition u/ais/nutrition –Read tennis fact sheet Complete review questions (p.355) –3, 4, 6, 7, 8, 9, 10