Hydration Flashcards
Water makes up about ___% of body weight.
60%
2/3 of water in _____, 1/3 ______.
- intracellular (within cells)
- extracellular
What does water do in the body?
- Acts as a solvent: solutes (for example: glucose, proteins,
minerals) dissolve in water - Participates in chemical reactions
- Transports nutrients, oxygen, hormones, waste materials, etc.
- Protects and cushions body structures
- Regulates pH and temperature
Is water stored?
no
Water intake must ____ water output.
equal
How do we intake water?
- consumption of water, fluids, foods
- production during cellular respiration
how do we output water?
- excretion in urine and feces
- sweating and evaporation from the skin and from the lungs
How is thirst stimulated?
- decreased blood volume, increased solute concentration
- decreased saliva secretion = dry mouth
- stimulates thirst centre
- thirst
- person takes a drink
- increased blood volume, decreased solute concentration
How do kidneys act as a filter?
- Water moves from the blood into kidney tubules
- Blood cells and proteins are too large and remain in the blood
What happens to needed substances at the kidneys?
reabsorbed back into the blood
What happens to substances not needed at the kidneys?
excreted in urine
Regulation of blood volume and pressure is stimulated by 3 hormones:
- ADH
- Angiotensin II
- Aldosterone
Name 7 consequences of dehydration.
- Increases fatigue: impairment of motor skill control
- Mental function is reduced… impairment of decision-making and
ability to concentrate - Increased body temp (105 degrees F = heat stroke starts)
- Elevates heart rate, blood thickens
- Reduces BP
- Nitrates build up (dangerous levels) in the blood stream
- Kidney & brain damage (can even lead to seizures or death)
How can staying hydrated improve physical performance?
- Better concentration and focus
- Improves motor skill performance
- Feel less fatigued, remember energy isn’t just from CHOs!
- Keep heart rate and body temp in optimal zone
___% of water intake comes from beverage sources.
60%
___% of water intake comes from food sources.
40%
What is the RDI for water?
- males: 3.7 L/day
- females: 2.7 L/day
Fluid loss and hydration needs are affected by what 4 factors?
- Genetics (body size, amount we sweat -different for each)
- Fitness level (fitter people sweat earlier and > amount)
- Environment (hot environment/decreased humidity = more sweating)
- Exercise Intensity (intensity up = more sweat = > fluid loss)
Need increased water intake with:
- low calorie diet
- high salt diet
- high fibre diet
- alcohol intake
It’s common to lose ____ L of fluid per hour of exercise.
0.5-2.0 L
How can we figure out how much replacement fluid to drink?
- Weigh yourself before exercise… then again after
- One kilogram of BW lost = One liter of fluid
- Begin drinking early in exercise, even 2% dehydration measurably
impairs athletic performance (70 kg person X 2% = 1.4 kg lost = 1.4 L lost fluid in one hour)
- Hydrate during activity: 150-300 ml every 15-20 minutes during exercise or competition
What is water intoxication?
- overhydration
- water intake is greater than water loss
- sodium in blood is diluted (hyponatremia)
- tissue swelling
We should consume ___ % of fluid loss during activity within ____ hours.
- 150%
- 4 hours
When should you use sport drinks?
- Exercise involving very high sweat rates
- Exercise involving high intensity or long duration
- Exercise involving hot and/or humid conditions
- To speed up recovery after exercise - Fluid, carbs, sodium, potassium stores replenished
What makes a good sport drink?
- Non-carbonated water
- Sodium - prevents muscle cramping
- Flavor - helps athletes drink more fluids
- Carbs - sugar improves taste, blood glucose up, helps fuel muscles (30-60 grams of CHO per hour during exercise)
Evidence suggests energy drinks can cause:
- irregular heart beat
- heart attacks
- spike in BP
- blood clots
- seizures
The high concentrations of simple CHOs in energy drinks leads to:
- slows the fluid absorption rates
- hinder re-hydration during due to sweating
The high fructose corn-syrup in energy drinks leads to:
- higher amounts of ‘fat’ created in blood
- insulin spike and subsequent energy crash
- interference with fluid absorption
- stomach upset and act as a laxative
In large doses, energy drinks may cause:
- Light-headedness
- Diuretic effect (excess urination)
- Laxative effect
