Exam III Flashcards
1 kg is equal to how many pounds?
2.205 pounds
How many kcals are burned per liter of oxygen?
5 kcals
Increase in metabolism could account for a rise in core temperature of __ degrees Celsius every ____ minutes
1 degree Celsius
7-10 minutes
We can only tolerate a ___ degree increase in body temperature
5 degree Celsius
Athletes who use ___ increase their risk for heat related injuries
EPO
Whats the average hematocrit percentage?
40-45%
What’s our maximal sweat rate?
3.5 L/hr
What is considered the thermostat or regulator of body temperature?
Hypothalamus
The hypothalamus is regulated at ___ degrees
37 degrees Celsius
What are the two responses that the hypothalamus activates to adjust to heat?
Thermal receptors in the skin
Hypothalamic blood
What are the methods that can be used for heat conservation?
Radiation
Conduction
Convection
What methods can be used for heat loss?
Radiation
Conduction
Convection
Evaporation
What’s the difference between conduction and convection?
Conduction: Typically solid substances
Convection: Typically gases, or liquids.
What’s the major physiological defense against overheating during exercise?
Evaporation
What’s the major physiological defense against overheating at rest?
Convection
When you sweat you lose _______.
Sodium Chloride
How many sweat glands do we have?
2 to 4 million
How many mL of sweat do we see from insensible perspiration?
350 mL
Max sweating under optimal conditions is what?
30 ml/min
Each mL of sweat transfers __ kcals of heat energy
.58 kcals
During max sweating this would equate to __ kcal/min of exercise.
17.4 kcal/min
What effects sweat evaporation?
Surface exposed to environment
Temperature and relative humidity of ambient air
Convective air currents around body
The optimal dew point for evaporation is what?
40 mmHg
What an example of a condition where very little sweat evaporation occurs?
Warm, humid environments
Does sweating cool off the skin?
No
What cools off the skin?
Evaporation of sweat
We see an increase in what during dehydration?
Blood Na+
An increase in Blood Na+ causes what two things?
Triggers thirst receptors
Slows gastric emptying
When someone overheats we see a decrease in what?
Plasma volume
A decrease in plasma volume causes what?
Increase in peripheral blood flow to increase evaporation
Increase in sweat rate
Once overheating occurs what happens to peripheral blood flow and sweat rate?
They both decrease
What percentage of the cardiac output passes through the skin during extreme conditions?
15-25%
When overheating occurs what happens to the cardiac output?
Decreases
Evaporation reaches equilibrium within __ minutes.
30 minutes
Trained individuals see a ________ in sweat rate.
Increase
Which hormone is directly related to water retention?
ADH
Which hormone is indirectly related to water retention?
Aldosterone
Aldosterone reabsorbs what?
Sodium
What three things occur when fluid loss is greater than 5% of the body mass?
Impede heat dissipation
Diminish cardiovascular function
Diminish exercise capacity
In cold weather we see a _______ in urine production.
Increase
Diuretics reduce what?
Plasma volume
Vomiting and diarrhea can cause what?
Mineral loss
Muscle weakness
How many mL of fluid should you drink prior to exercise? How many minutes prior to exercise should you drink them?
400-600 mL
20 minutes prior
How many mL of water empties into the stomach?
1000 mL
How many mL of sweat loss occurs?
2000 mL
What range of mL of water should you drink every hour of exercise?
600-1000 mL
1 pound of weight loss is ___ mL of dehydration
450 mL
Consume an excess of ___ to ___ percent of existing fluid loss after exercise.
125-150%
Older individuals have a _______ thirst drive.
Depressed
What the recommended amount of sodium and potassium should you add to your drinks?
Sodium: 100 mmol/L
Potassium: 2-5 mmol/L
Increased sodium and potassium can have what three effects?
Increased osmolality
Less urine production
Restores plasma volume
Sweat loss can deplete the body of ___ g of salt
13-17g
The ACSM recommends how much sodium per L of water for events lasting more than an hour.
0.5-0.7g
What is hyponatremia?
Water intoxication
Heat acclimation occurs after how many days?
10 days
How long does it take to lose heat acclimation?
2-3 weeks
What are some benefits of heat acclimation?
Increased sweat production
Decreased heart rate
Decrease in core body temperature
Which gender produces less sweat?
Women
Why do women produce less sweat?
Greater body mass to lean muscle mass ration
What are the three major heat related illnesses? (Rank them in terms of less severe to most severe)
- Heat cramps
- Heat exhaustion
- Heat stroke
True or False: Oral temperature is just as accurate as core temperature?
False
How many mg of caffeine must you consume for caffeine to act as a diuretic?
500 mg
Caffeine is a ___ stimulant
CNS
Whey protein comes from what?
Cow’s milk
What are the three types of whey protein?
Concentrate (Contains lactose)
Isolate
Hydrolysate (Partially Broken Down)
Whey protein is an excellent source of what?
BCAAs and Amino Acids
What’s the major amino acid in whey?
Leucine
What percentage of leucine is found in whey?
> 10%
Soy protein comes from where?
Plant source
What are the two types of soy protein?
Concentrate and Isolate
What’s unique about soy protein concentrate?
Is without water-soluble carbs
What is unique about soy protein isolate?
Most of the fat and carbs are removed
Soy is high in what?
Arginine and Glutamine
Whats the major function of arginine and glutamine?
Immune system boosters
Which protein increases lean muscle mass? What molecule is the major reason for this?
Whey, Leucine
Creatine is produced how?
Endogenously
How much creatine do we produce each day?
1 gram
Where is creatine largely produced?
Liver, kidneys, pancreas
Where is creatine found? What’s the percent breakdown for each?
Muscle Mass (95%)
Brain, Liver, Kidney, Testes (5%)
What are the two major forms of creatine? What’s the percent breakdown for each?
Phosphorylated (60%)
Free Form (40%)
How is creatine pool effected?
Fiber type, and skeletal muscle mass
Which fiber type has the greatest effect on the creatine pool?
Type II
What three amino acids are required for creatine synthesis?
Arginine, Glycine, Methionine
What’s the major creatine transporter?
CreaT1
CreaT1 is sensitive to what?
The intracellular amount of creatine
What are some of the performance improvements we see from creatine?
Increase in 1 RM
Increase in Endurance Strength
What increase do we see in muscle hypertrophy after a 5 day creatine loading phase?
Collagen mRNA
GLUT4
Myosin Heavy Chain IIA
What’s a major reason for creatine’s benefits in performance?
Decreases muscle growth inhibitors
Increases satellite cell proliferation
Increase in IGF-1 (Major Reason)
Creatine causes what improvements in anaerobic perofrmance?
Improvement in <30s activity
Slight improvement in 30-150s exercise
What’s the typical loading dose for creatine?
20 g/day or 0.3 g/kg/d
What’s the typical amount recommended for creatine during a maintenance phase?
3-5 g/d
What is the major mechanism for creatine’s effect on anaerobic performance?
Facilitates re-uptake of Ca2+ into Sarcoplasmic Reticulum, allowing for faster detachment of actomyosin cross bridge
This produces more force on the next impulse
When you’re anemic you have a drop in ______ which causes you to become _______.
RBC
Hypoxic
When you’re anemic and low in RBC, what should you take/produce?
EPO
What’s the process of producing new RBC?
Kidneys produce EPO, which leads to the formation of RBC in the bone marrow
Cold weather has what effect on the respiratory passage?
Increases the loss of water through the respiratory passage
Caffeine increases what?
Recruitment of motor units
Mobilization of FFA
Mobilization of Calcium in Sarcoplasmic Reticulum
Caffeine speeds what?
Neuron Firing
Neuron firing causes what reaction?
Causes you to feel alert
Caffeine stimulates ______ to secrete ________?
Pituitary gland
Adrenaline
Caffeine inhibits what?
cAMP Phosphodiesterase (2nd messenger)
Caffeine manipulates what?
Dopamine
When does caffeine absorption occurs?
45 minutes
Where does caffeine absorption occur?
Stomach and Small Intestine
Peak concentration of caffeine is within ______.
1.5 Hours
What’s the half-life of caffeine?
3-7 hours
Adenosine is a _______.
Neuromodulator
Adenosine inhibits the release of _________.
Neurotransmitters (A:1 Presynaptic Cleft)
What are the neurotransmitters that are inhibited by adenosine?
Glutamine GABA Norepinephrine Serotonin Acetylcholine
Adenosine hinders _______
Adenylyl Cyclase
Adenylyl Cyclase decreases
cAMP Levels
Adenosine blocks what?
Pre-synaptic Calcium Channels
Adenosine stimulates what?
Potassium Channels
Caffeine is metabolized where?
Liver
What enzyme helps metabolize caffeine?
CYP1A2 Isozyme
Caffeine is an antagonist to what?
Adenosine Receptors
Peripheral fatigue is due to an increase in what?
Hydrogen Ions
Potassium Ions
Phosphate
Metabolic Fuel Sources
_______ is directly related to exercise induced acidosis.
H+ concentration
What are some symptoms of exercise induced acidosis?
Dysfunction of sarcoplasmic reticulum
Reduced cross bridge
Increased Potassium release
Decrease in PFK activity
Chemical formula for bicarbonate?
NaHCO3
Bicarbonate increases what?
Extracellular HCO3- and pH
Bicarbonate stimulates what?
Lactate
H+ Cotransporter
High-intensity exercise and bicarbonate
Events lasting more than 30 seconds
Repeated sprinting
Combat Sports
Prolonged bouts of exercise (60+ min)
Dose and loading time for bicarbonate
0.3 k/kg
What’s the peak time to consume HCO3?
60-180 minutes prior to exercise (consuming with carbs is debatable)
Additional benefits of bicarbonate
Reduces exercise-induced oxygen desaturation in arteries
Decreases rating of perceived exertion during exercise
Nitrates plasma concentrate peaks when?
1-2 hours
Nitrate converts to what? When does it peak?
Nitrite
2-3 hours
Whats another term for hypoxia?
Deoxyhemoglobin
What are some sources of nitrate?
Lettuce, spinach, celery
Does Nitrate work?
Yes
Used in experimentation, this method shows no change in caloric content.
Isocaloric
Nitrate can increase what?
Vasodilation
Angiogensis
Glucose Uptake
SR Ca+ Handling
What are two immune system boosters?
Arginine and Glutamine
Caffeine is seen as a ______ aid.
Ergogenic aid
What is the superfamily of enzymes?
Cytochrome P450
CYP1A2 isozyme can also be expressed as
Cytochrome P450 1A2
Caffeine is metabolized into what? What is the percent breakdown?
Paraxanthine (84%)
Theobromine (12%)
Theophylline (4%)
Paraxanthine increases what?
Lipolysis
Theobromine is associated with what and increases what?
Vasodilation
Increases urine production
Theophylline is what?
A smooth muscle relaxer of bronchi
What substance found in energy drinks was shown to have a big effect in the study?
Taurine
How long do you have to go without caffeine to see an effect if you are a regular user?
3 days
When do trained individuals see the impact of caffeine?
In the morning
Did caffeine show improvements in sprinting?
No
Do regular users see the effect of caffeine?
No
The caffeine study was what type of analysis?
Meta-analysis
Nitrate can cause what?
Fatigue resistance
Exercise efficiency
Exercise performance
In the protein study, what substance was used to test that the subjects were following the diet?
PABA
The buffering of ______ ion allows us to be in a ______ state
H+
Aerobic
_____ is responsible for mitochondrial growth
PGC-1A
PGC-1A is responsible for what. And decreases the reliance of what as a fuel source?
Mitochondrial growth
Lactate
The caffeine study used what scale to assess the results?
PEDro Scale