Card Set Information

2013-11-03 12:02:32
Fluid electrolyte challenges exercise

fluid and electrolyte
Show Answers:

  1. what are the 9 fxns of water in the body:
    • forms the fluid portion of blood
    • maintains blood volume
    • participates in metabolic rxns
    • serves as a solvent for proteins, glucose, vitamins, and minerals
    • forms fluid portion of sweat (cooling)
    • carries heat from inside the body to the skin (cooling)
    • lubricates joints
    • forms spinal & eye fluid
    • forms amniotic fluid in the womb
  2. what are the three ways water can be "taken into" or generated in the body:
    • liquids: water, milk, juice, ect.
    • foods: shrimp, bananas, corn, potatoes
    • metabolic water: water generated by metabolic rxns
  3. the amount of water needed to be ingested varies with what 3 things:
    • phyiscal activity performed
    • environmental temperature
    • environmental humidity
  4. how much water is lost from the body per day?

    how much water should be ingested to maitain normal hydration:
    • h2o lost from the body per day: 2.5 L
    • ingested to maintain hydration: total water intake need to match total water loss
  5. a normal hydration level is called:
  6. net water loss, leading to dehydration is called:
  7. how much water is typically lost throughout the day in the following mediums:

    • urine: 500-1400 ml
    • sweat: 400-900 mL (with exercise)
    • feces: 150 mL
    • insensieble perspriation: 350 mL
    • total per day: 1400-2800 mL per day
  8. mineral salts that dissolve in water and form ions are called:
  9. charged molecules are called: ions

    positively charged molecules are called:
    negatively charged molecules are called:
    • charged molecules are called: ions
    • postitively charged molecules are called: cations
    • negatively charged molecues are called: anions
  10. what are the 3 important fxns of electrolytes:
    • allow electrical charges to occur
    • essential to excitable tissues ( neurons & muscle fibers)
    • create force (osmotic pressure) to hold water & move it through membranes as needed
  11. the force created to draw water thru a memebrane is called:

    how do cells indirectly controll the movement of water:

    what mechanism allows this to indirect movement to occur:
    the force created to draw water thru a memebrane is called: osmotic pressure

    • -cells indirectly control the movement of water by directly controlling the movements of electrolytes, since water follows electrolytes
    • -mechanism: sodium-potassium pump
  12. if a membrane permable to water seperates two volumes how does water move if.....

    there are equal concentrations of electrolytes:
    if there are more electrolytes on one side of the membrane:
    • equal concentrations of electrolytes: no tendency for water to move in either direction
    • more electrolytes on one side of the membrane: tendency for water to move toward the side of the membrane with greater concentrations of electrolytes
  13. how is electrolyte balance controlled within the body:
    • kidneys
    • if Na+ content is low, kidneys conserve Na+ by reabsorbing from urine
    • controlled by hormonal mechanisms: aldosterone; conservation of sodium

    • gastrointestinal tract
    • absorbs minerals (mineral salts dissolve in water, forming electrolytes) ((then into bloodstream))
  14. a fluid that has a lower osmotic pressure than that of blood is called:

    give an example:
    • a fluid that has a lower osmotic pressure than that of blood is called: hypotonic
    • example: sweat
    • seat has fewer electrolytes than does blood
    • in intense exercise/heat 3-4 L hr-1 of sweat can be lost
  15. list 4 adaptions of sweat due to the acclimatization to heat:
    • higher sweat rate
    • ealier onset of sweating
    • increased plasma volume
    • reduced electrolyte content of sweat

    • -although, fewer electrolytes are lost per volume of sweat to maintain balance
    • -GI and Kidneys are capable of reabsorbing electrolytes, discouraging imbalances
  16. urine electrolyte content of urine will vary to help ensure electrolyte balance:

    how does urine electrolyte content vary during exercise compared to at rest:

    what 2 factors vary sodium excretion:
    during exercise: as intensity increases, sodium excretion decreases

    • 2 factors of sodium excretion
    • less sodium excreted per liter of urine
    • urine output increase from rest to light exercise then decreases during moderate exercise
  17. a conscious desire to drink and is involved in maintaining hydration and water balance is called:

    how is this mechanism controlled in the brain:
    • a conscious desire to drink and is involved in maintaining hydration and water balance is called: thrist
    • brain control: hypothalamus that sense plasma osmolality
  18. how is the thrist mechanism typically stimulated:

    as fluid is ingested, what happens to the concentration of dissolved fluids:
    • how is the thrist mechanism typically stimulated: when body water is lost, the concentration of dissolved substances within the blood adn bodily fluids increase
    • as fluid is ingested, what happens to the concentration of dissolved fluids:  concentration of dissolved fluids returns toward normal, drive to drink diminshes

    • humans are slow hydrators
    • thrist mechanism does not result in restoration of water balance quickly
    •  becuase of this... athletes should consume fluids before starting the exercise session
  19. during exercise, dehydration commonly results due to:
    dehydration results due to: sweating
  20. the mechanism of dissipating the heat generated by the increased burning of energy is called:

    the effectiveness of this mechanism depends on:
    • sweating
    • effectivness depends on: relative humidity in the environment (more effective in dryer)
  21. water lost thru sweating comes from 4 areas in addition to sweat glands:
    • intracellular and extracelluar compartments (plasma)
    • muscle tissue & skin
    • internal organs
    • bones
  22. how is the cardiovascular system compromised by dehydration for aerobic capabilities:
    • decreased plasam volume
    • decreased stroke volume
    • increased heart rate

    • these 3 attempt to maintain cardiac output
    • (Q=HR x SV)

    decreased cardiac output

    increased systemic resistance (vasoconstriction)

    decreased blood pressure
  23. how is thermoregulation compromised by dehydration for aerobic capabilities:
    • increased core temperature: hyperthermia
    • decrease in skin blood flow
    • decreased sweat rate

    diminishing the ability to dissapate heat
  24. how are metabolic fnxs compromised as a result of dehydration:
    • increased glycogen as a metabolic substrate
    • increased blood lactate levels

    these factors decrease preformance due to fatigue from increase glycogen and increased acidity

    • decreased VO2peak
    • deacreased peak lactate value
    • decreased lactate threshold
  25. are the effects of dehydration more likely to affect anaerobic or aerobic performance:

    dehydraption is more likely to affect: aerobic performance

    • why
    • Decrease in plasma volume & cardiac output don’t affect anaerobic activity 
    • Anaerobic capability decrements more likely with heat exposure
    • Strength decrements more likely in upper body
  26. the primary goals of fluid ingestion during a marathon event is:

    what are 2 factors that affect the amount of fluid intake needed for a marathon:
    • 2 goals
    • prevent dehydration
    • electrolyte replacement

    • 2 factors that affect the amount
    • the greater the body mass, the greater then fluid intake needed
    • the greater the heat & humidity, the greater the fluid intake needed

    • endurance capabilities are decreased by dehydration of as little as 2% of total body mass
    • programmed and ad libitum drinking can be used to maintain hydration during a marathon
  27. wrestlers typically lost 5-6% of total body mass  to make a weight class, how is this usually accomplished:

    how does dehydration of 5-6% impact the performance:
    • loss of total body mass accomplished by: caloric and fluid restriction
    • dehydration of 5-6% results in: decrements in strength and anaerobic performance
    • decreases were a result of combined effect of weight loss, dehydration, & competing in tournament
  28. how can dehydration affect the performance in team ball sports:
    • decreased aerobic performance in later stages of contest
    • decreased anaerobic capabilities (sprinting)
    • decreased power/strength (jumping)
  29. how can dehydration affect the performance in a baskeball team:

    how can dehydration affect the performance ina soccer team:
    • decreased shooting percentage (8%)
    • decreased sprint ability percentage (2%)
    • decreased lateral movement ability (5%)

    soccer: decreased performance of yo-yo intermittent recovery test ( by 15%)
  30. list the factors that can predispose individual or groups to dehydration:
    • envrionmental factors: high temperature or high humidity
    • athletes who dehydrate to make a weight class
    • protective equimpent: interfere w/ heat loss
    • dark colored clothing: greater heat absorption, increased sweating
    • illness: fever or diarrhea
    • age: loss of extracelluar fluid, decreased plasma volume, decreased osmolarity
  31. list and describe the 2 methods of field hydration assesment methods:
    • assesment of body mass
    • euhydration: maintenacne within +- 1% of per-exercise value
    • dehydration: losses > 1% of pre-exercise body mass

    • assesment of urine color
    • euhydration: light color
    • dehydration: dark color
    • may be skewed if taking supplements (darken urine) or drinking fluids after an exercise sessio
  32. water intoxication due to a low blood sodium concentration is called:

    this condition results in an osmotic imbalance which can lead to:
    • hyponatremia
    • osmotic imbalance can lead to: fluid movement into the brain, causing swelling of the brain (disorientation, confusion, weakness, grand mal seizures, coma, death)
    • can also be caused by excessive sodium lost in sweat
    • more likely in women than in men
  33. the guidelines for fluid consumption

    begin activity in a euhydrated state:
    maintain hydration during activity:
    rehydrate after activity:
    • begin activity in a euhydrated state: 17-20oz 2 to 3 hours before event, 200-300 mL 10 to 20 mintues before event
    • maintain hydration during activity: 200-300 mL every 10 to 20 minutes
    • rehydrate after activity: within 2 hours, drink enought fluid to replace lost body weight, for rapid rehydration drink 25-50% more fluid than sweat lost
    • fluids should be palatable, cool, and contain electrolytes
  34. describe how to develop a hydration plan
    • indiviudalized hydration
    • plan will be modified with changing seasons and conditions