SportsNutrition_Chapter8_Water

1,768 views

Published on

This online lecture features information about water and sport performance.

0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,768
On SlideShare
0
From Embeds
0
Number of Embeds
271
Actions
Shares
0
Downloads
51
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

SportsNutrition_Chapter8_Water

  1. 1. Water Chapter 8
  2. 2. Water <ul><li>Arguably the most essential nutrient </li></ul><ul><li>Restriction can lead to death in days </li></ul><ul><li>Slight dehydration decreases performance </li></ul>Photo © Photodisc
  3. 3. Body Water <ul><li>Constitutes 60% of body weight </li></ul><ul><li>Types of body water </li></ul><ul><ul><li>Intracellular (inside cells) </li></ul></ul><ul><ul><ul><li>Two-thirds of body water </li></ul></ul></ul><ul><ul><li>Extracellular (outside cells) </li></ul></ul><ul><ul><ul><li>One-third of body water </li></ul></ul></ul><ul><ul><ul><li>Lymph, blood plasma, etc. </li></ul></ul></ul>
  4. 4. Functions of Water <ul><li>Provides cell structure </li></ul><ul><li>Serves as reactive medium </li></ul><ul><li>Provides for cooling </li></ul><ul><li>Assists in pH balance </li></ul><ul><li>Major constituent of blood volume </li></ul>
  5. 5. Sources of Water <ul><li>Approximately 80% from ingested fluids </li></ul><ul><ul><li>Milk, sports drinks, juices, other beverages </li></ul></ul><ul><ul><li>Caffeinated drinks can count </li></ul></ul><ul><ul><li>Bottled water (Is it the best?) </li></ul></ul><ul><li>< 20% from ingested foods </li></ul><ul><ul><li>Fruits, vegetables, etc. </li></ul></ul><ul><li>Remainder formed during metabolism </li></ul>
  6. 6. Avenues of Water Loss <ul><li>Urination </li></ul><ul><ul><li>Major avenue of loss during rest </li></ul></ul><ul><li>Defecation </li></ul><ul><li>Sweating </li></ul><ul><ul><li>Major avenue of loss during exercise </li></ul></ul><ul><li>Insensible perspiration </li></ul>
  7. 7. Water Balance Water intake < Water Loss Dehydration Water intake = Water Loss Balance Water intake > Water Loss Hyperhydration
  8. 8. Effects of Dehydration
  9. 9. Effects of Dehydration (continued)
  10. 10. Effects of Hyperhydration <ul><li>Usually not a problem </li></ul><ul><ul><li>Can be beneficial </li></ul></ul><ul><li>Hyponatremia (water intoxication) </li></ul><ul><ul><li>Excessive hyperhydration </li></ul></ul><ul><ul><li>Extensive sweating with only water replacement </li></ul></ul><ul><ul><li>Most common in ultra-endurance events </li></ul></ul>
  11. 11. Monitoring Hydration Level <ul><li>Monitor body weight fluctuations </li></ul><ul><ul><li>Pre- and post-workout </li></ul></ul><ul><ul><li>From day to day (same time) </li></ul></ul><ul><ul><li>2 to 3 cups per pound lost </li></ul></ul><ul><li>Monitor urine color </li></ul><ul><li>Monitor urine specific gravity </li></ul>
  12. 12. Hydration Level and Urine Color
  13. 13. Current Recommendations for Water Intake
  14. 14. How can water intake for athletes be estimated? <ul><li>Calculate based on daily energy expenditure </li></ul><ul><ul><li>1 milliliter of water/1 kcal expended </li></ul></ul><ul><ul><li>1 cup = 240 milliliters </li></ul></ul><ul><li>Then add the amount of water lost due to sweating </li></ul><ul><ul><li>2 to 3 cups for every pound lost during the workout or competition session </li></ul></ul>
  15. 15. Fluid Sources of Water <ul><li>There are many choices </li></ul><ul><li>Each offers benefits </li></ul><ul><li>Examples </li></ul><ul><ul><li>Milk </li></ul></ul><ul><ul><li>Juices </li></ul></ul><ul><ul><li>Sport drinks </li></ul></ul><ul><ul><li>Tea </li></ul></ul>
  16. 16. Food Sources of Water
  17. 17. Practical Suggestions for Staying Hydrated <ul><li>Calculate individual needs. </li></ul><ul><li>Ideal hydration leads to urination every 1 to 2 hours. </li></ul><ul><li>Maintain pale urine. </li></ul><ul><li>Get daily fluids from a variety of sources. </li></ul><ul><li>Consume caffeinated drinks in moderation. </li></ul><ul><li>Don’t overdo protein consumption. </li></ul><ul><li>Be conscious of the effects of medications on hydration levels. </li></ul>
  18. 18. Factors Affecting Hydration Needs <ul><li>Environmental temperature </li></ul><ul><li>Acclimatization of athlete </li></ul><ul><li>Altitude </li></ul><ul><li>Fitness level of athlete </li></ul><ul><li>Others? </li></ul>
  19. 19. Preexercise Hydration: How Much? <ul><li>24 hours prior </li></ul><ul><ul><li>Meet predetermined fluid needs </li></ul></ul><ul><li>2 to 3 hours prior </li></ul><ul><ul><li>400 to 600 milliliters (i.e., approx. 2 to 3 cups) </li></ul></ul><ul><li>10 to 20 minutes prior </li></ul><ul><ul><li>200 to 300 milliliters (i.e., approx. 1 cup) </li></ul></ul>
  20. 20. Preexercise Hydration: What Type? <ul><li>Variety is good </li></ul><ul><li>Water </li></ul><ul><li>Juices </li></ul><ul><li>Milk </li></ul><ul><li>Sports drinks (+/-) </li></ul><ul><li>Caffeinated drinks? </li></ul><ul><li>Carbonated drinks not recommended </li></ul>Photo © Liquid Library Photo © AbleStock Photo © PhotoDisc
  21. 21. Hydration During Exercise: How Much? <ul><li>Purpose </li></ul><ul><ul><li>Maintain hydration </li></ul></ul><ul><ul><li>Maintain electrolytes </li></ul></ul><ul><li>200 to 300 milliliters (i.e., about ~1–1.5 cups) </li></ul><ul><ul><li>Sweat trials can help determine ideal fluid intake </li></ul></ul><ul><li>Every 10 to 20 minutes </li></ul><ul><li>Thirst is not a good guide </li></ul>Photo © Photos.com
  22. 22. Hydration During Exercise: What Type? <ul><li>Water is excellent </li></ul><ul><li>Sport beverages: </li></ul><ul><ul><li>If taste is preferred over water </li></ul></ul><ul><ul><li>If practice or event lasts longer than 60 to 90 minutes </li></ul></ul><ul><ul><li>6–8% carbohydrate mix </li></ul></ul><ul><li>Fruit juices are not recommended </li></ul>Photo © Photos.com
  23. 23. Practical Guidelines for Keeping Athletes Hydrated During Exercise <ul><li>Fluids should be readily available. </li></ul><ul><li>Fluids being consumed should be based on personal preference for taste. </li></ul><ul><li>Regular and frequent breaks should be allowed. </li></ul><ul><li>Start ingesting fluids early during exercise before getting thirsty. </li></ul><ul><li>Drink cool fluids (50 – 59 o F) rather than warm ones. </li></ul><ul><li>Have athletes practice staying hydrated during training not just during competition. </li></ul>
  24. 24. Postexercise Hydration <ul><li>Begin rehydrating as soon as possible. </li></ul><ul><li>Drinks and foods containing carbohydrates and sodium are good choices. </li></ul><ul><li>Plan ahead and have drinks readily available. </li></ul><ul><li>Avoid drinking large quantities in a short time. </li></ul><ul><li>Drink 2 to 3 cups of fluid for every pound lost. </li></ul>

×