wk4 Flashcards
what are the functions of water
- Nutrient transport
- Protection
- Temperature regulation
- Biochemical reactions
- Medium for reactions
what are the ways we lose fluid
- Respiration
- Skin
- Faeces
- Urine
what are the ways we gain fluid
- Drink
- Food
- Metabolic
what is euhydration
when water input = output
what is dehydration
when water output > input
what is hyperhydration
when water input > output
what is hypohydration
when the body water deficit is greater than normal daily fluctuation, we normally measure this through change in body weight. Body mass loss of >= 2%
what is osmolality
measure the total dissolved particle concentration (mOsm/kg)
why do we need to rehydrate
sweat loss causes viscous blood, need to rehydrate to make it easier to pump blood
what occurs to plasma osmalality during exercise
it increases as we sweat more, leading to less water and higher conc of ions
what doess water loss cause in terms of ability
impairs one’s ability to perform in aerobic events, strength and power however will be less effected
what factors affected by water loss will inhibt aerobic performance
- Cardiovascular – bp. Blood-flow, o2 delivery and metabolite removal
- CNS – brain metabolism, brain temp
- Peripheral muscular factors – temp, metabolic, afferent feedback
- Psychological – thermal comfort, perceived exertion
- Respiration – breathing sensations
how much should you drink before exercise
2-4hrs before, 5-10ml/kg bw
how much should you be drinking during exercise
enough to limits bw loss to < 2%, typically 0.4-8 L/H
how much should you be drinking after exercise
around 1.25L for every kg lost during exercise
why is sodium good for the body
- Pre exercise – helps with fluid retention
- During exercise – limits electrolyte losses, stimulates thirst
- Post exercise – restoration of sodium and fluid balance
how to calculate sweat rate
(weight loss + volume consumed - urine loss) / duration
what should a carbohydrate sodium solution contain
- 80-350kcal/L energy from CHO
- 20-50mmol/L of sodium
what is hyponatremia
low blood sodium < 135mmol/L, can be caused by drinking too much water and diluting your blood stream. More risk for women and recreational athletes
what are the symptoms of hyponatremia
- Nausea
- Fatigue
- Seizures
- Weakness
- Low BP
after exercise how do we maintain good fluid/sodium balance
consume drink of 125% sodium concentration to reach breakeven levels
