Check your understanding and practice midterm questions Flashcards
Your TA is walking to the bus, then runs as fast as possible for 2 minutes.
- does he generate more pyruvate running or walking?
- what determines if aerobic or anaerobic glycolysis will occur?
- what molecule is required for work?
- which form of glycolysis generates the most work?
- running
- oxygen supply and exercise duration
- ATP
- aerobic glycolysis
A student rides a bike where work increases by 50W every 2 minutes until they are exhausted.
- how do ATP demands change? What is the primary signal?
- where is energy to generate ATP coming from? how does it change/how do we measure?
- what regulates change in energy sources?
- why not use the same energy source at all times
- ATP demands increase with intensity of the exercise. Main signal is low ATP levels?
- comes from macronutrients and chemical bonds. measure via RER?
- duration/intensity of exercise, oxygen supply
- because PCr runs out, anaerobic glycolysis produces lactate and acidity, and aerobic is slow.
An athlete cycles a workload which elicits 95% of their VO2 max, and they go until they can’t after 15 minutes
- what mechanisms might account for this?
- genetics, training level, insufficient oxygen consumption/supply, mitochondrial density, lactate threshold/ventilatory threshold
A varsity rugby player and an untrained student race 400m. who do you think has the highest blood lactate at the end of the race and why?
The varsity athlete! They will have much more efficient anaerobic pathways, and a higher tolerance for pyruvate. they will move a lot faster than the untrained, meaning they will produce a lot more pyruvate
Without warming up a runner goes on a hilly 10km run and maintains a velocity of 10km/h
Sketch their: ATP demands, oxygen consumption, oxygen deficit and EPOC
competition rock climbing routes take 2-6 minutes to complete. What strategies might they use to recover between routes 1 hour apart
- proper breathing (slowed down)
- ## cool down to use up their lactate and prevent accumulation
A friend rides an exercise bike everyday until it says they have burned 500kcal. they then drink a 150kcal sport drink for recovery. they complain they don’t lose weight, what do you say?
Your calorie intake cannot exceed the amount of calories that you burn. Although there is a net burn of calories, they should focus on lowering their calorie intake since it is likely that they are consuming more calories at other meals/times of day. drink water instead of a sports drink.
two friends go for a run at 10km/hour. one is talking in full sentences and the other can only get out a few words. how is their physiology different during the run?
the one talking in full sentences is operating at a lower VO2 max than the other friend. it is likely that the one talking has increased mitochondria density, higher training level, higher VO2 max, more efficient systems, and higher ventilatory threshold
Describe how increased oxidative phosphorylation would alter the partial pressure of O2 and CO2 at diff locations throughout the body
venous blood = increased PCO2, decreased PO2
arteries = PO2 and PCO2 remain unchanged
tissues= increased PCO2, decreased PO2
lungs= increased PCO2, decreased PO2
how might the body maintain homeostasis by minimizing changes in gas partial pressures?
CO2 buffers
1. renal buffer
2. ventilatory buffer
3. chemical buffer
- bicarbonate, protein and carbonic acid?
- shunting
why is the amount of oxygen dissolved in blood important?
because it drives the unloading and saturation of oxygen to hemoglobin/myoglobin
determines the aerobic capacity of an individual
why would hemoglobin have less affinity for oxygen as exercise increases
- because of the bohr effect. increases in acidity and temperature result in less affinity for oxygen, prompting higher unloading
What regulates a-vo2 difference? why is it different at the heart vs arteries
- regulated by the rate of metabolism within the muscles. higher metabolism of oxygen means less O2 in veins, and a higher a-vo2 diff
- at the heart, a-vo2 diff is really high. muscles will have varying a-vo2 levels
what forms of doping might increase the amount of oxygen carried in the blood? how would they increase performance?
- blood doping: adding hematocrit
- training at altitude: training at high altitudes gets your body to accumulate itself to low oxygen supply. this means that when you compete or exercise at regular altitude, your body is going to be significantly more efficient
describe what signals increase ventilation, how they are detected and how this changes during exercises
- signals: decrease in parasympathetic drive, increase in norepinphrine/epinephrine (cornotropic/inotropic)
- detected via….
- with exercise intesnity increasing, decrease in parasympathetic drive will have less of a role. it will be more attributable to sympathetic stimulation
explain the mechanism of increased ventilatory equivalents above lactate threshold
- anaerobic predomination (more lactate production)
- efficient buffering of acidity through ventilation?
describe how ventilation can regulate blood activity
increase inspiration is in response to elevated CO2/H levels in the blood. by increasing respiration, more hydrogen and CO2 is eliminated, therefore decreasing acidity levels and restoring the acid base balance?
apply the lactate/ventilatory concept to predict endurance exercise performance and prescribe training intesity
high lactate/ventilatory thresholds = higher training status/aerobic capacity = higher VO2 max
Prescription of training will depend on the individual’s goals, but if they are looking to improve aerobic capabilities, typically this is what we would prescribe
- Frequency - 3-4days a week
- Intensity - 80+% VO2 max if you are looking to improve VO2, roughly 60-70% for maintenance
- Type - aerobic activities, running, jogging, cycling
- Time - Depends on capabilities, most important thing is pushing yourself. For novice, 10-15 minutes is a good goal, then work up to 30+ minutes
define the work of breathing, describe how it changes with exercise intensity and alters performance
W = f x d
f = pressure
d = volume changes????
idk. I’d think that increases in work mean increases in exercise, since you’re taking deeper breaths? but the deep breaths might mean that you are slowing down. idk
a younger sibling challenges you to a breath hold. what strategy would you use?
hyperventilation. it decreases PCO2 to about 15mmHg, so that you have more time and more CO2 production before you hit the threshold for breathing, which is at 50mmHg
how might the regulation of breathing differ in vancouver vs everest base camp
vancouver = higher oxygen levels, more oxygen supply to muscles, better efficiency
everest = low oxygen levels, less supply, less efficiency?????
how would eating baking soda (NaHCO3) alter ventilation in the first few seconds of exercise and the first few minutes
baking soda is basic. it would alter the pH of your blood to be less acidic.
first seconds = decreased inspiration, since acidity is so low
first few minutes = you can operate at a higher intensity since your blood is more basic, you have more range of CO2 production????
describe how different modes of exercise alter blood pressure
start: increased HR and Q
high intensity: bp rises a lot
aerobic: vasodilation decreases BP temporarily
post exercise: Bp returns to baseline
overtime: lower BP
when measuring arterial oxygen saturation would it matter if you sampled blood from arteries supply active vs in active muscle?
No! it is uniform throughout the body. it would matter if you were looking at the partial pressure
how would the heart behave without chemical or neural inputs
- no parasympathetic or sympathetic means you are unable to change HR
- pace will stay at around 100bpm
Why does blood pressure increase during exercise? how does the type of exercise affect this?
because we have a higher demand for oxygen, increasing Q and HR, all of which increase BP, along with vascular resistance adjustments
Aerobic = vasodilation = temporary decrease BP
anaerobic = increased BP
