Msk 7 Flashcards
What does proper hydration do for body weight?
Maintains body weight +/- 1%
Dehydration with what % body loss affects physical performance?
2% or more
Prolonged intense exercise can increase water requirements up to
10 L
What are Sx of dehydration?
thirst
dizziness
tachycardia
oral mucosal moisture imprecise measurements
Proper hydration should have what urine specific gravity and concentration & plasma osmolality?
Urine SG <700 mOsm/kg
Po = 280-290 mOsm/kg
High protein diets require additional water to clear what substance?
Urea nitrogen
True or false. Proper hydration may include quick fluid replacement if necessary.
False. Rapid replacement increases urine loss. Proper replacement should be in 20-30 min aliquots to improve retention
Dehydration in excess of ____% body mass can compromise physiologic function.
2%
What % dehydration are these symptoms seen:
Thirst
Increased rectal temperature
1%
What % dehydration are these symptoms seen:
Performance decrements seen
Decreased heart SV & increased HR; decreased PV
2%
What % dehydration are these symptoms seen:
Performance further declined
Decreased blood to kidneys, skin, & muscles
3-4%
What % dehydration are these symptoms seen:
Decreased work capacity 20-30%; sweat rate decreases, spasms & cramping occur
Heat cramps; increased susceptibility to heat exhaustion; decreased nutrient & oxygen supply to the kidney
5-10%
What % dehydration are these symptoms seen:
Unable to continue exercise
Heat stroke; can be fatal
> 10%
An athlete drinks fluids with carbohydrates in them, consumes 30-60 g/hr of carbs, and the fluid contains 500-700 mg/L Na content. What type of activity is this athlete preparing for?
Vigorous activity >1hr
vs. activity <1hr when water replacement alone is adequate
What is the primary electrolyte lost in sweat and in what concentration?
Sodium 1-5 g/L
During rehydration, how can hyponatremia result?
water replacement without Na after high volume sweat loss
What are the 4 primary sources of ATP for muscle contraction?
Muscle-stored ATP
Phosphocreatine-creatine system
Glycogen-lactic acid
Aerobic system
How long does muscle-stored ATP provide the muscles with enery?
~3 seconds of high intensity activity
very limited muscle store of ATP
How and how long does the Phosphocreatine-creatine system provide muscles with energy?
High energy phosphate bond
rapid conversion of ADP to ATP
Immediate source of energy 4x faster than aerobic met.
Limited supply - 8-10 sec
Which source of energy utilizes anaerobic metabolism?
Glycogen-Lactic Acid
- glycogenolysis –> glucose –> glycolysis
- inefficient; only uses 6% of glucose energy content
- rapid; 2.5x faster than aerobic metabolism
What is the primary energy source for muscles at rest & low intensity exercise?
Fat (aerobic)
What is the primary energy source for muscles with moderate & intense exercise (300-400+ Kcal/Hr)?
Glucose & glycogen (aerobic)
Which energy source is essential for endurance activities?
Muscle glycogen (aerobic)
How much protein is lost daily due to obligatory protein loss?
20-30 g protein daily
