Lecture 34 Flashcards
Hydration
what is hyperhydration
more body water than normal
what is hypohydration
less body water than normal
what is euhydration
normal body water
what is dehydration
losing body water
what is rehydration
gaining body water
the volume and composition of body fluid are both important, both are detected and controlled precisely by …..
- blood pressure receptors
- osmoreceptors
sweat causes plasma osmolarity to increase, what hormone will be released because of this change
vasopressin which will cause vasoconstriction to maintain blood pressure
body fluid is maintained precisely with a change of less than ….. per day
+ or - 0.5L
increased osmolarity of body fluids inhibits what
inhibits sweating
what state of hydration could you be in and not realise
hypoantraemic and hyperhydrated
how much water can the stomach empty in an hour (average)
average of 1L per hour
what does increased osmolarity and decreased blood volume cause
- decreased thermoregulatory efficiency
- increased cardiovascular strain
what is meant by thermoregulatory efficiency is decreased when osmolarity increases and blood volume decreases
- increased sweating threshold and decreased sensitivity
- increased skin blood flow threshold and decreased sensitivity
what is meant by cardiovascular strain is increased when osmolarity increases and blood volume decreases
decreased stroke volume
increased heart rate
decreased cardiac output
what are the positives to using the alternative view of drink to thirst
- avoids exercise associated hyponatraemia
- no performance benefit shown for drinking beyond thirst
- safe
what performance is most effected by hypohydration
endurance
what is the IF dehydration …… and the AND high…….. that leads to THEN dehydration makes heat illness more likely
IF dehydration increases body temperature AND high body temperature facilitates heat illnesses THEN dehydration makes heat illness more likely
optimal hydration for training is …
unclear
hypohydration impairs anabolic response, so suggested…
rehydrate well in recovery (especially resistance)
for performance try to limit body mass loss to (hydration)
2-4% of your initial mass
recommendations of hydration before exercise
~0.5L at 3-4 hours before (with CHO and salt)
~0.2L <30 min; unless running hard
recommendations of hydration during exercise
~600ml per hour