Exercise Physio part 2 Flashcards
What are some characteristics of anaerobic ATP production? What are sources of this type of ATP production? What are characteristics of aerobic ATP production?
Anaerobic ATP production is faster to turn on, very powerful for maxing out ATP turnover rate, but limited to sustain repeated contractions; stored ATP, ADP+ADP, creatine phosphate, glycolysis; slower to turn on, less powerful than anaerobic, but can sustain longer bouts of muscle contraction
When is anaerobic ATP production important?
Transition period from one level of activity to higher level, and when exercise demands exceed anaerobic threshold of individual
When someone exercises and ATP demand is immediate, what is used? What does this cause early in the transition from rest to ATP production? What is incurred consequently when we no longer need ATP?
Anaerobic production of ATP; O2 deficit; O2 debt
Besides immediate use of ATP, when might we see anaerobic ATP production? What is the normal threshold, and what can it be in trained individuals? What levels would indicate this anaerobic ATP production?
At the anaerobic threshold, when at some percent of max VdotO2 we use anaerobic mechanisms to produce ATP; 50-60%, vs. 85-90% in trained individuals; muscle lactate concentrations
What four components does RER (respiratory exchange rate) depend on? With increased exercise intensity, what do you expect to see with RER? What does this indicate?
- Exercise intensity 2. Prior dietary history 3. Exercise duration 4. Fitness level; The RER will go up because you’re using more carbs relative to fat, and you’re also hyperventilating more
With prolonged work, what do you expect to see with RER provided that you’re on a certain diet? When could you see fatigue? What is the effect tied in to this? On average, who would have a higher RER in terms of diets?
You would see the RER drop because you’d use carb stores early but eventually you begin to use fat more for energy; is someone does not have carbs in their diet in the recent history (couple days); glucose/glycogen sparing effect!! The person on a high carb diet
During exercise, why are you still able to take up glucose?
Increased insulin sensitivity allowing for glucose uptake even in the presence of stress like exercise (symp drive)
With respect to prolonged exercise, is there much concern for people working at e.g. 50 or 70% of their max Vdot O2? When would you begin to be concerned and what would you take to deal with this? When would you have severe local muscle fatigue?
No (can keep blood glucose levels at aroud 80% even after a couple hours); 3-5 hours, when patients are exhausted and they can take glucose supplements; when you’ve depleted your muscle glycogen
How does glycogen utilization increase with exercise intensity (VdotO2)? What can prevent the profound local muscle fatigue due to glycogen depletion?
Exponentially; Glycogen loading prior to exercise
At which percent of VO2 max is _______ the major cause of fatigue? At other percents, what contributes to fatigue?
75; glycogen depletion; Must be other factors
What can stimulate utilization of blood free FA’s by skeletal muscle? What inhibits it? In trained dogs, how much plasma FFA’s do you see relative to untrained ones? Who generates more lactate? In general, what does a more fit person use at any exercise intensity relative to unfit people?
Epi, norepi, GH, glucagon, and cortisol; lactate and insulin; Considerably more; The untrained dogs; more fatty acids contributing to a lower RER, whereas untrained person uses more carbs and could deplete their glycogen rapidly
What does being bed-ridden do to VO2max? How long does it take for fit and unfit individuals to recover? Can we alter our VO2 max with training?
Decreases!; 2 months; Probably not, given there’s a genetically limited peak, so wanting it enough is NOT ENOUGH!
What is VO2max the product of? What is the cause for one of these terms increasing?
max a-v O2 difference and max cardiac output; for max a-v O2 difference, you could see in well-trained people having increased capillary density (increased SA and decreased diffusion distance) and increased mito content with more and larger mito
Is there any difference in max heart rate between trained and untrained individuals? How does a well-trained individual attain a higher O2 consumption level?
No, but well-trained individuals will have lower HR’s during submaximal exercise; through lower HR’s and higher SV’s (lower end-systolic volume!!)
What is RPP? When is it higher/lower? What are the consequences?
HR x SBP; lower at any given work rate in fit vs unfit (lower HR!!); Heart requires less O2, blood flow, and can deliver same CO at lower HR
