1. Sports Nutrition BTEC L3 Sport Gatorade!

2. Learning Outcomes Students shall develop knowledge of hydration and sports drinks. Students shall learn how to calculate sweat rates and dehydration status. Students shall learn how to make their own sports drinks. 3. Hydration Key Terms Thermoregulation The ability to keep the bodys temperature constant, even if the surrounding temperature is different. Ergogenic Aid a substance that improves exercise performance. 4. Functions of Water (H20) Eliminates waste products (urine, faeces) Transport materials around the body Regulate body temperature (thermoregulation) Cushion joints how? Keeps skin moist (the worlds cheapest and most effective beauty treatment) Fact! brains are 75% water. bones are 25% water. blood is 83% water. 5. Water Main transport mechanism - carries nutrients and waste products Vital for thermoregulation Aids the passage of food through digestive system Water makes up approx. 60% of your total body weight, (this depends on age, sex and body composition). A human contain 30-50 litres of H2O! Fact! Leaner individuals contain more water than fatter people of the same mass..... 6. Average fluid balance values for humans Water Input Water Output Source ml Source ml Fluids 1,200 Urine 1,250 Food 1,000 Skin 850 Metabolism 350 Lungs 350 Faeces 100 Total 2,550 Total 2,550 7. De-hydration Hinders performance by affecting strength, power, coordination and aerobic endurance, (virtually all CoFs!) Severe dehydration can cause heat stroke and can be fatal!!! Signs & Symptoms Lack of energy and early fatigue during exercise Feeling hot Clammy or flushed skin Not needing to go to the toilet Headache Disorientation Shortness of breath Poor performance (mental & physical) 8. Hydration Terminology De-hydration Excessive loss of water from the body Re-hydration Replacing fluids lost through exercise. Hypo-hydration In a state of decreased hydration, less than normal water content in the body, (impairs thermoregulation). Hyper-hydration Increased hydration from normal (can improve thermoregulation). Super-hydration A state hydration achieved by manipulation with the ergogenic aid glycerol, (glycerol has shown to increase water retention). A strategy to reduce heat stress in hot environments 9. Adverse effects of dehydration 1% - Threshold of Thirst. 2% - Stronger thirst, discomfort, loss of appetite, impaired performance. 3% - Dry mouth, decrease in blood plasma and urinary output. 4% - 20-40% decrease in work capacity (max. physical work). 5% - Impaired concentration, headache, impatience, sleepiness/drowsiness. 6% - Severe impairment of thermoregulation during exercise, increased heart rate. >7% Collapse, dizziness, loss of balance, delirium, exhaustion. 10%+ Organ failure death! 10. Body weight loss (%) ExerciseCapacity 0 21 3 4 5 60% 80% 100% In cool laboratory conditions, VO2 max has been shown to decrease with fluid losses, (as little as 2% loss body mass) In the heat, sweat rates increase even more, such that fluid intake must be even more closely monitored. 11. 1 2 3 4 5 6 7 8 Urine Color Chart Assess Hydration 1, 2, or 3: Well Hydrated 4 or Darker: Dehydrated How do athletes monitor hydration & rehydration? 12. How much should athletes drink during exercise? Fluid requirements vary remarkably between athletes and between exercise situations. Factors affecting fluid loss; Genetics - some people innately sweat more than others. Body size - larger athletes tend to sweat more than smaller athletes. Fitness - fitter people sweat earlier in exercise and in larger volumes. Environment - sweat losses are higher in hot, humid conditions. 13. How can I tell how much Im sweating? Pre exercise weight 70 kg Post-exercise weight 68.5 kg Volume of fluid consumed during exercise 1l (kg) Exercise duration 2 h Calculations Fluid deficit (l) = 70 kg - 68.5kg = 1.5 kg Total sweat loss (l) = 1.5 kg + 1 kg = 2.5 kg Sweat rate (l/h) = 2.5 kg / 2hr = 1.25 l/h 14. Calculating sweat rates An 78kg male takes part in a 1.5 hour pre season football training session and drinks 500ml litre (0.5kg) of water during the session. After he weighs himself, he now weighs 74kg. What was his sweat rate? Answer = 3 litres per hour!!! (78-74+0.5=4.5l / 1.5h = 3l) This is roughly how much fluid you would lose through sweat on a warm day during a match!!! 15. Dehydration Status This athlete has lost 4kg of body mass through fluid loss, he is obviously now dehydrated. He should normally weigh 78kg, how dehydrated is he? (answer in % age) Answer Roughly 5%!!! Effect on performance???? Note: - Athletes need to train themselves to drink, especially in hot conditions. 16. Calculating sweat rates An 55kg female takes part in a 45 min high intensity intermittent sprint training session and drinks 500ml litre (0.5kg) of sports drink during the session. After she weighs himself, he now weighs 53kg. What was her sweat rate? Answer = 3.33 litres per hour!!! (55-53+0.5= 2.5l/0.75h = 3.33l) 17. Dehydration Status This athlete has lost 2kg of body mass through fluid loss, she is obviously now dehydrated. She should normally weigh 55kg, how dehydrated is he? (answer in % age) Answer Roughly 3.5%!!! Effect on performance???? +10% affect on her training??? 18. Effect on Performance references! Armstrong (1985) Dehydration by as little as 2% can decrease performance in 5 and 10km races by 6-7%. Nielsen (1981) Dehydration by 2.5% decrease capacity to perform high intensity exercise performance by 45%. Saltin and Costill (1988) Dehydration by 5% decreases work capacity by 30%. Maughan (2000) 3% dehydration will reduce overall (most aspects of) performance by 10% 19. Body weight loss (%) ExerciseCapacity 0 21 3 4 5 60% 80% 100% In cool laboratory conditions, VO2 max has been shown to decrease with fluid losses, (as little as 2% loss body mass) In the heat, sweat rates increase even more, such that fluid intake must be even more closely monitored. 20. Dehydration The volume of fluid that most athletes choose to drink voluntarily during exercise replaces less than one-half of their body fluid losses! (Noakes et al., Exercise Sports Science Review, 1993) It is just as important for athletes to train their stomachs to drink as it is for them to train their muscles! 21. Physiological effects of dehydration Impaired thermoregulation (temperature control) Decreased sweat rates Decreased blood flow to skin Greater increase in core temp. during exercise Reduced tolerance to heat strain Decreased stroke volume Increase heart rate All these factors dramatically affect performance! 22. Sports Drinks vs Water? Why are sports drinks a more effective way of rehydrating athletes than just drinking water? 1. Re-hydrate quicker and more effectively than water, (absorption rates) 2. Provide extra energy 3. Prolong the effects of fatigue 4. Replaces sweat losses Can be expensive (make your own) 23. Sports Drinks vs Water? Most sports drinks aim to provide three nutrients; what are they? 1. Carbohydrate to replace energy 2. Water to replace fluid lost in sweat 3. Electrolytes which are?????? Minerals lost in sweat e.g. Sodium, potassium, magnesium, calcium etc. 24. Sport Drinks Ingredients Carbohydrate Glucose, fructose, maltodextrins Enhance performance, fluid absorption and palatability Electrolytes Sodium, potassium, chloride, calcium, magnesium Enhance water absorption, palatability Maintains thirst Prevents hyponatraemia (water intoxication) Caffeine? Can enhance endurance performance Can improve alertness Potential negative effects though, not for everyone! 25. Sport Drinks Sports Drinks can be Isotonic, Hypotonic or Hypertonic What does this mean? Water = 0% CHO Isotonic = 4-8% CHO Similar to body fluid Hypotonic = 8% CHO More than 26. Sport Drinks Hypertonic slow rate of absorption, usually consumed with other fluids, best used in recovery stages. Isotonic usually contain sodium to speed up absorption. Can be used before exercise. Hypotonic These can be more effective than water as they can encourage fluid replacement through enhanced taste. 27. Fluid Intake Pre-event Athlete should be fully hydrated, at least 300- 500ml 10-15 minutes before exercise is recommended. Inter-event 150-200ml every 15-20 minutes. Post-event 150% of sweat rate. 28. Fluid Intake Re-hydration Strategies Sweat Losses Intermittent Exercise Football/Rugby match = 1-4 litres! How much should an athlete drink? Note: this is only a guide many factors can/will affect this! Before During After 300-500ml 10-15 minutes before start of activity 150-200ml every 15-20 minutes 150% of sweat rate (up to 6 hrs post exercise) 29. Sports Drink Recipe 1. 100ml fruit squash (non sugar free) 400ml water 1 small pinch of salt Mix thoroughly and chill 30. Sports Drink Recipe 2. 250ml fruit juice (no added sugar) orange, apple etc. 250ml water 1 small pinch of salt Mix thoroughly and chill 31. Sports Drink Recipe 3. More precise if you want exact CHO concentration e.g. 6% 800ml warm water 200ml sugar free squash (taste) 60g of glucose power 1 pinch of salt Mix thoroughly and chill 32. Factors to consider when using Sports Drinks Palatability Athlete preference? Solid Food (i.e. banana) + water Hydrate before exercise What is available? Sports Drinks At least 1% CHO 20-30mg/l of sodium 5-10mg/l of potassium 33. Remember The greater the F.I.T.T of exercise, the more important fluid replacement strategies become..... Food Water Sports drinks 34. Activities (P5, P7, M4, D2) 1. Devise a simple five point plan to ensure that sports people maintain an adequate state of hydration, (tips to stay hydrated). (this plan can be used later on in the unit when formulating diet plans). 2. Research and find at least 8-10 different sports drinks that are commonly used by athletes and list their ingredients in terms of carbohydrate and electrolytes State whether they are hypotonic, hypertonic or isotonic. For each drink then state what stage of training/competition they would by useful for, (pre, during, post-exercise). Extension Find out what effect taking the supplement glycerol has on hydration.