W3 - Priming, Pacing & Prior Exercise Flashcards
What does the study of VO2 kinetics refer to?
Looking at subjects O2 consumption + its response through time.
Why might it be beneficial to “speed up” VO2 kinetics?
To incorporate the use of aerobic energy systems
Therefore reduce reliance on anaerobic systems
What are the key components of VO2 kinetics?
Baseline
Amplitude
Time delay
Time constant
What are the 3 phases of pulmonary VO2 kinetics?
Cardiodynamic phase
Muscle VO2 phase
Steady state phase
Phases of pulmonary VO2 kinetics
Cardiodynamic phase
Immediate increase in CO, breathing rate + bf at onset of exercise
Lasts 15-20s
Phases of pulmonary VO2 kinetics
Muscle VO2 phase
Exponential phase
Reflects what’s occurring in the muscle
Phases of pulmonary VO2 kinetics
Steady state phase
ATP demand is being met by oxidative phosphorylation
What is meant by time constant
Time taken to reach 63% of the response
What is 1 time constant
Time taken to reach 63% of the response
What is 2 time constant
63% plus another 63% of what’s remaining
What is 4 time constant
Basically steady state
What sized time constant is a good thing?
Small
What does fast kinetics result in?
Slow o2 deficit
= Positive impact on performance
What does slow kinetics mean in regards to energy systems?
Slow kinetics means one is relying on their anaerobic fuel sources
When might larger O2 deficits occur
In situations with slow kinetics, so greater reliance on anaerobic energy sources.
What would a larger O2 deficit mean?
Greater PCr breakdown
Greater ADP + Pi accumulation
Greater H+ + lactate accumulation
Greater rate of glycogen degradation
What would speeding the rate of O2 uptake do to muscle PCr + glycogen and why?
Spare muscle PCr + glycogen due to using oxidative energy systems earlier in the exercise.
= Less accumulation of H+ + Pi.
How can speeding up VO2 kinetics be achieved?
Endurance training
Delta
Difference between ones GE threshold or LT + their VO2 max
Exercising at 50, 70, 80% delta means…
One will be exercising above their GE threshold
How can improved VO2 kinetics impact SEVERE intensity exercise?
Can ⬆️ oxidative energy provision.
By ⬇️ O2 deficit we can preserved PCr + glycogen stores, ⬇️ metabolite accumulation + ⬇️ ADP, Pi, H+ + lactate accumulation
Does a low intensity warm up before the athletes performance improve their VO2 kinetic response?
NO
No faster response
No reduced slow component
No increase of primary amplitude,
How does completing prior exercise above LT change VO2 kinetics?
for SEVERE-intensity exercise
Faster response
Greater primary amplitude
Decreases VO2 slow component
How does completing prior exercise above LT change VO2 kinetics?
for EXTREME-intensity exercise
Greater primary amplitude
Attainment of the VO2 max
Peripheral measures of influence of prior exercise
O2 dissociation curve is shifted to the right
Muscle O2 extraction increases
Increased Muscle VO2
Influence of prior exercise on anaerobic metabolism
⬆️ oxidative energy provision = ⬇️ requirement for anaerobic energy provision = ⬇️ lactate production
What is currently thought to be the “optimal” warm-up?
Pre-exercise blood [lactate] at ~3mM
Prior high intensity exercise coupled w/ sufficient recovery optimises the balance between preserving the effects of prior exercise on VO2 kinetics + providing sufficient time for the muscle homeostasis to be restored.
What are the pacing strategies?
ES (Even start)
SS (Slow start)
FS (Fast start)
What is the error signal?
Difference from where we are + where we need to be.
In which pacing strategy would you expect to see a bigger error signal?
Fast start
What would manipulating the error signal do?
Could alter VO2 kinetics + the O2 deficit thus alter performance
Fast start accelerates VO2 kinetics to…
Provide greater oxidative metabolism
= Sparing anaerobic sources so improved TTE?
What is significantly related to the acceleration of the VO2 kinetic response with fast start technique?
Improvement in performance TTE
What has an ALL-OUT start improved?
High intensity, short duration kayak performance
Due to seeing a much faster, reactive kinetic response compared to an even pace .
What are the important considerations for pacing
Event duration
Starting intensity
Starting duration
Physiological mechanisms
Priming + pacing?
Results from a fast start 3 min trial
Faster VO2 kinetics + attainment of vO2 max
Greater oxidative metabolism
Sparing of PCr + glycogen, reduced H+ + Pi
Sig greater 60s sprint capacity after 2 mins of work-matched exercise
Which displays faster O2 uptake kinetics?
All-out start or fast start
All-out start
Self-paced TT or All-out start to accelerate vO2 kinetics?
All-out start
What does combining an all-out start with severe intensity priming exercise do?
Accelerates VO2 kinetics
Synergistically improves 4-km TT performance to a greater extent than either pacing or priming separately
