Athletes need both!                      1
Heat Removal• Exercise increases core temperature.   For every L of O2 consumed during   exercise ~5 kcal is produced but ...
Sweating and Fluid Loss• Mild to moderate work and routine  physical training typically result in  whole-body sweat losses...
Avoid “Hitting the Wall”
In cool laboratory conditions, VO2max has been shown to     decrease with fluid losses > 2% BW...     In the heat, sweat r...
Effects of dehydration on sportsperformance. % OF BODY WEIGHT      PHYSIOLOGICAL EFFECT  LOST AS SWEAT       4%           ...
How does sweating (fluid loss) work to decreaseperformance?           increase in plasma osmolarity (higher           conc...
Daily Water BalanceAthletes need to be fully hydrated before training/competitionThe average sedentary person excretes abo...
Athletes and Daily Water Balance
Water Balance: Normal25002000                           Metab                               Food1500                      ...
Water Output:        Normal vs.Exercise50004000                                Stool3000                                Br...
Water Intake:        Normal vs Exercise500040003000                            Metab                                Food20...
In comparison to non-athletes:• Athletes greatly increase their water loss  – Large increases in sweat loss  – Some decrea...
Guidelines1. Intake approximately 500ml. (2 cups) of a cool   beverage 2 hours before a workout, 250ml (1   cup) in final ...
•   Hydrate properly before prolonged exercise in hot    environments.•   Water is the ideal fluid replacement, although f...
Sports DrinksTYPE        CONTENTISOTONIC    FLUID, ELECTROLYTES , 6-8%            CARBOHYDRATEHYPOTONIC   FLUID , ELECTROL...
The osmolality of a fluid is a measure of the number of particles in a   solution.In a drink, these particles will compris...
Isotonic - quickly replaces fluids lost by sweating and supplies a   boost of carbohydrate. This drink is the choice for m...
SALTINSIDE CELL               OUTSIDE CELL              DEHYDRATION                              WATER
ELECTROLYTES Electrolytes are electrically charged particles thatconduct electricity as they dissolve in liquids such as  ...
SODIUM “ THE YOUTH ELEMENT”•   Keeps joints limber•   60% is present in the fluid outside the cell;10% is present    insid...
POTASSIUM “THE ALKALISER”• Makes up 5% of the mineral content of the body.• Plays a vital role in making muscle protein fr...
FUNCTIONS OF ELECTROLYTES• Regulates water balance• Interacts with the cell membranes to allow nutrients  to enter cells a...
BODY WATER             60% OF           BODY WEIGHT                           20%   40%                          EXTRA  IN...
WATER BALANCE   Drinking H2O            Food stuffs                                                   Metabolic   & bevera...
INTERESTING FACTS ON WATER•   Water delivery inside the cells is more effective in the nights    when the body is horizont...
Heat and Sweat Production During                   Exercise• Evaporate 1 liter sweat  = 580 Cal heat• 720 Cal heat =  evap...
Strategies for Avoiding Dehydration• Establish a hydration  protocol for athletes• Determine individual sweat rate   – Cha...
Strategies for Avoiding DehydrationEmphasize continual fluid replacement• Replace fluids as they are lost• Practice fluid ...
Strategies for Avoiding Dehydration• Understand each athlete’s sport dynamics   – Rest breaks/time outs   – Fluid accessib...
Strategies for Avoiding Dehydration• Anticipate high risk conditions• High temperature  – Uniform/clothing effects• High h...
Strategies for Avoiding Dehydration• Hyperhydration  – 500 ml, 15-30 minutes prior to exercise  – Limited benefits• Post-e...
Example:•   Joe played tennis for two hours( 120 mins). He drank    a 500ml bottle of water during his workout.    – Initi...
Sport Drinks Water, CHO, electrolytes replacement during exercise• Provide water• Provide dilute carbohydrates  – should b...
Carbohydrates in Sport Drinks• Glucose   – rapidly absorbed and utilized by muscle• Fructose   – more slowly absorbed and ...
Sport Drinks• Provide electrolytes during  exercise  – replace Na and Cl lost in sweat  – enhances water uptake     • [NaC...
Homemade Sport Drink•    lemonade mix(nimbu pani powder)•   1000ml water•   ¼ - ½ tsp salt•   6 tablespoon Glucose•   1 ta...
Sports Hydration - Mount Carmel College- Sports Nutrition credit course
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Sports Hydration - Mount Carmel College- Sports Nutrition credit course

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How Hydration strategies are practiced in Sports Nutrition

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Sports Hydration - Mount Carmel College- Sports Nutrition credit course

  1. 1. Athletes need both! 1
  2. 2. Heat Removal• Exercise increases core temperature. For every L of O2 consumed during exercise ~5 kcal is produced but only 1kcal is used for mechanical work – the rest is heat• Increases in core temperature: – Increase blood flow to the skin – Initiate sweating
  3. 3. Sweating and Fluid Loss• Mild to moderate work and routine physical training typically result in whole-body sweat losses of about ~0.8-1.4 L/h.• Evaporation of 1L of water from the skin will remove 573 kcal of heat from the body.• Heat loss via evaporation of sweat is largely dependent on the humidity (proximate to the skin) in which the athlete is working.• Individual sweat rates and fluid losses vary widely between athletes and across sports.
  4. 4. Avoid “Hitting the Wall”
  5. 5. In cool laboratory conditions, VO2max has been shown to decrease with fluid losses > 2% BW... In the heat, sweat rates increase even more such that fluid intake must be even more closely monitored. 100% 80%CapacityExercise 60% 0 1 2 3 4 5 Body weight loss
  6. 6. Effects of dehydration on sportsperformance. % OF BODY WEIGHT PHYSIOLOGICAL EFFECT LOST AS SWEAT 4% CAPACITY FOR MUSCULAR DECREASES 5% HEAT EXHAUSTION 7% HALLUCINATIONS 10% CIRCULATORY COLLAPSE / HEAT STROKES
  7. 7. How does sweating (fluid loss) work to decreaseperformance? increase in plasma osmolarity (higher concentration of solute in solution) release of vasopressin (ADH) from the posterior pituitary gland. ADH causes the kidney to re-absorb water Urine volume goes DOWN dramatically to preserve blood osmolarity, volume and pressure As exercise progresses, the transfer of body water into the plasma cannot keep up with
  8. 8. Daily Water BalanceAthletes need to be fully hydrated before training/competitionThe average sedentary person excretes about2700 milliliters of water/day (1400 from urine, 1100sweat/breath)To replace that 2700 ml, get:• 300-400 ml from metabolism,• 1000 ml from food and• 1300-1400 ml from beverages 2700 ml
  9. 9. Athletes and Daily Water Balance
  10. 10. Water Balance: Normal25002000 Metab Food1500 Fluids Stool1000 Breath Sweat Urine500 0 Output Intake
  11. 11. Water Output: Normal vs.Exercise50004000 Stool3000 Breath Sweat2000 Urine1000 0 Normal Exercise
  12. 12. Water Intake: Normal vs Exercise500040003000 Metab Food2000 Fluids1000 0 Normal Exercise
  13. 13. In comparison to non-athletes:• Athletes greatly increase their water loss – Large increases in sweat loss – Some decreases in urine loss• Athletes need to greatly increase water intake – Large increases in fluid consumption – Smaller increases in food water and metabolic water – Athletes often fail to consume adequate amounts of fluids to maintain optimal hydration status
  14. 14. Guidelines1. Intake approximately 500ml. (2 cups) of a cool beverage 2 hours before a workout, 250ml (1 cup) in final 15-30 minutes.2. During activity, drink fluid frequently- for example, 150 -200ml(1 cup) every 15-20 minutes.3. After a workout, replenish fluids at a rate of 1litre for every kilogram of body weight lost. Weight should be regained, before the next workout, indicating rehydration.
  15. 15. • Hydrate properly before prolonged exercise in hot environments.• Water is the ideal fluid replacement, although flavored beverages may be more effective at promoting drinking.• The salt in the beverages or as food can promote rehydration more effectively than plain water when significant weight loss has occurred through sweating.• Urine should be pale yellow or clear. This indicates that you are in a hydrated status
  16. 16. Sports DrinksTYPE CONTENTISOTONIC FLUID, ELECTROLYTES , 6-8% CARBOHYDRATEHYPOTONIC FLUID , ELECTROLYTES , LOW CARBOHYDRATEHYPERTONIC HIGH LEVEL OF CARBOHYDRATE
  17. 17. The osmolality of a fluid is a measure of the number of particles in a solution.In a drink, these particles will comprise of carbohydrate, electrolytes, sweeteners and preservatives.In blood plasma the particles will comprise of sodium, proteins and glucose.Blood has an osmolality of 280 to 330mOsm/kg. Drinks with an osmolality of 270 to 330mOsm/kg are said to be in balance with the bodys fluid and are called Isotonic.Hypotonic fluids have fewer particles than blood and Hypertonic have more particles than blood.Consuming fluids with a low osmolality, e.g. water, results in a fall in the blood plasma osmolality and reduces the drive to drink well before sufficient fluid has been consumed to replace losses.
  18. 18. Isotonic - quickly replaces fluids lost by sweating and supplies a boost of carbohydrate. This drink is the choice for most athletes - middle and long distance running or team sports. Glucose is the bodys preferred source of energy therefore it may be appropriate to consume Isotonic drinks where the carbohydrate source is glucose in a concentration of 6% to 8% - e.g. High Five, SiS Go, Boots Isotonic, Lucozade Sport.Hypotonic - quickly replaces fluids lost by sweating. Suitable for athletes who need fluid without the boost of carbohydrate e.g. jockeys and gymnasts.Hypertonic - used to supplement daily carbohydrate intake normally after exercise to top up muscle glycogen stores. In ultra distance events, high levels of energy are required and Hypertonic drinks can be taken during exercise to meet the energy demands. If used during exercise Hypertonic drinks need to be used in conjunction with Isotonic drinks to replace fluids.
  19. 19. SALTINSIDE CELL OUTSIDE CELL DEHYDRATION WATER
  20. 20. ELECTROLYTES Electrolytes are electrically charged particles thatconduct electricity as they dissolve in liquids such as water or blood.
  21. 21. SODIUM “ THE YOUTH ELEMENT”• Keeps joints limber• 60% is present in the fluid outside the cell;10% is present inside the cell;30% is present in the bones.• Excessive sweat causes sodium loss as in  Hard manual labor  Professional athletes  Starvation  Vomiting & diarrhoea
  22. 22. POTASSIUM “THE ALKALISER”• Makes up 5% of the mineral content of the body.• Plays a vital role in making muscle protein from amino acids.• Concentration of sodium and potassium are inversely proportional to each other.• Dehydration depletes potassium and increase muscle breakdown
  23. 23. FUNCTIONS OF ELECTROLYTES• Regulates water balance• Interacts with the cell membranes to allow nutrients to enter cells and waste to leave• Maintains acid-base balance• Conducts nerve impulse
  24. 24. BODY WATER 60% OF BODY WEIGHT 20% 40% EXTRA INTRA CELLULARCELLULAR
  25. 25. WATER BALANCE Drinking H2O Food stuffs Metabolic & beverages 700 ml water 300ml 1500 ml Body water Urine Feces Skin Lungs1500 ml 150 ml 450 ml 400 ml
  26. 26. INTERESTING FACTS ON WATER• Water delivery inside the cells is more effective in the nights when the body is horizontal• When we drink enough water to pass clear urine, we also pass out a lot of the salt that was held back• Nothing kills life quicker than lack of water• The salinity of the water outside the cells in our bodies is the same as the ocean
  27. 27. Heat and Sweat Production During Exercise• Evaporate 1 liter sweat = 580 Cal heat• 720 Cal heat = evaporates 1.24 liters of sweat• Real conditions, approx. 2 liters
  28. 28. Strategies for Avoiding Dehydration• Establish a hydration protocol for athletes• Determine individual sweat rate – Changes in body weight (pre- post weighings) – 1 kg = 1043ml additional fluids during exercise – May also account for urine volume – Goal: no weight loss (or < 2% wt loss) – Urine color or urine specific gravity
  29. 29. Strategies for Avoiding DehydrationEmphasize continual fluid replacement• Replace fluids as they are lost• Practice fluid replacement – Gradually increase fluids – Body adapts to increase fluid consumption – Generally, cold fluids more rapidly absorbed• Use individual clear bottles for visual monitoring• Old Rule of Thumb: – 0.5-1 cup per 10-15 min – Individualize is far better
  30. 30. Strategies for Avoiding Dehydration• Understand each athlete’s sport dynamics – Rest breaks/time outs – Fluid accessibility• Establish athlete’s acclimatized state – Non-Acclimatized athletes • sweat more • lose more electrolytes
  31. 31. Strategies for Avoiding Dehydration• Anticipate high risk conditions• High temperature – Uniform/clothing effects• High humidity – Indoor sports – Uniform/clothing effects• Low air movement – Uniform/clothing effects• Bright sun – Dark colored clothing
  32. 32. Strategies for Avoiding Dehydration• Hyperhydration – 500 ml, 15-30 minutes prior to exercise – Limited benefits• Post-exercise rehydration – Ideally completed within 2 hrs • ACSM/ADA rec: 700ml per 500gms body weight lost • Replace CHO and electrolytes at same time to speed rehydration
  33. 33. Example:• Joe played tennis for two hours( 120 mins). He drank a 500ml bottle of water during his workout. – Initial weight = 70 – Post-exercise weight = 68• Water loss =70-68 = 2 kgs• % body weight loss = 2/70 = 2.8% (dehydrated)• Total sweat loss = approx 2 litres• To stay hydrated within 2% (minimum fluid replacement rate) – 2% x 70 = 1.4 kgs allowed wt loss = 1.4 litres allowable sweat loss• Maximum fluid replacement rate – 1.4 lits/ 120 min = 11ml/min = 175 ml every 15 min• Recommended fluid replacement (per 15 min) – 2.5-10 oz every 15 min
  34. 34. Sport Drinks Water, CHO, electrolytes replacement during exercise• Provide water• Provide dilute carbohydrates – should be < 10% (<8% optimal) – Gatorade: G+S @ 6% – Powerade: F+GP @ 8% – Fruit juice: F+S @ 11-15% – Soft drinks: F @ 11%
  35. 35. Carbohydrates in Sport Drinks• Glucose – rapidly absorbed and utilized by muscle• Fructose – more slowly absorbed and utilized by liver to replace liver glycogen• Sucrose (G-F)• Glucose Polymers – lower osmolarity than simple sugars and may allow for more rapid water absorption
  36. 36. Sport Drinks• Provide electrolytes during exercise – replace Na and Cl lost in sweat – enhances water uptake • [NaCl] < 1000mg/L – Gatorade: Na,Cl,K,P (460mg/L) – Powerade: (Na,Cl) (300mg/L) – Orange Juice: (10 mg Na/L) – Soft drinks: (40 mg Na/L)
  37. 37. Homemade Sport Drink• lemonade mix(nimbu pani powder)• 1000ml water• ¼ - ½ tsp salt• 6 tablespoon Glucose• 1 tablespoon Sucrose• ½ tbsp baking powder

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