Lecture 10 - Pacing Flashcards
In normal exercise why does the muscle become initially less acidic with the onset of exercise ?
The reaction of creatine kinase to breakdown and resythisize PCr utilises a Pi, reducing the level of acidity.
This is why acidity levels fall initially.
Define a slow start pacing strategy?
The race is commenced with a low velocity with the race pace increasing over the course of the race.
What is another effect of fast starting that can assist VO2 ?
Starting faster also results in a higher blood flow the the working muscles, meaning greater O2 delivery
For events lasting 5-30 minutes what seems to be the consensus for pacing ?
An even pacing throughout with a sprint at the end.
With performance why can sometimes being the faster athletes to cover the event distance not result in the first place position ?
This can be because despite the athlete running the distance faster because of how they position them self throughout the race they may have in-fact covered more distance than the total for the race, whereas the winner may have covered less total distance, and thus come in first place.
Definition of an even pace racing strategy ?
Race pace is kept very close to the mean race pace cross the event with little deviation.
Over the course or a marathon how can dietary interventions effect performance ?
In the first half of a race nutrition does not really come into play, however when athletes are given increased sodium, carbohydrate and caffeine intakes compared to a group who were not given these this resulted in a better maintenance of mean race pace.
Of these three carbohydrate is the most important as have been shown to have a similar effect just on its own.
Why is a fast start better at enhancing 1-5 minute race performance ?
It works by increase the oxygen uptake, VO2 and pulmonary O2, therefore increases the oxidative energy contributions.
This means that they are using less anaerobic metabolism, resulting in less acidity and glycogen useage.
What stimulates O2 consumption in the mitochondria ?
- Changes in the extramitochondrial phosphorylation potential: (ATP/ADP x Pi)
- Accumulation of ADP, Pi and other products of ATP and PCr hydrolysis
In events lasting less than one minute, what is the best pacing strategy ?
All out pace strategy.
So what does the increased blood flow and faster changes in metabolic disturbance result in for why fast starts are beneficial ?
The greater changes in phosphorous metabolites when starting faster/with a higher power output signal a more rapid adjustment in muscle VO2 and greater O2 consumption.
What is another benefit of maneuvering your position within racing evens that can result in improved performance ?
Being with the pack can improve economy because of reductions in wind resistance, however exposes you to group slowing ect.
When events last over 30 minutes what is the best pacing method ?
Even pace with little deviation form the mean race pace.
What has been shown as another method when doing an all out start to enhance performance ?
Combining this this a 3 minute high intensity warm up, followed by 20 minutes of recovery results in a higher mean power output and faster time to completion.
This works by increasing the VO2 at baseline, 2 mins and at the end of exercise, as well improving the response time and O2 consumption.
What is the Fick equation ?
VO2 = CO x a-VO2 difference
This is the difference between O2 delivery and O2 extraction.
(The CO AND a represent the central delivery.
Define a fast start pacing strategy ?
The race is commenced with a high velocity with the race pace declining over the course of the race.
What are the four types of racing strategy ?
- Even pace
- Fast start
- All out
- Slow start
What can happen if a fast start or all out start is performed for to long in an event ?
It causes to much or a decline in carbohydrate and PCr stores, and results in a falling of muscle PH into acidic conditions causing fatiguing symptoms.
With endurance events what is considered the best pacing strategy, especially as the distance increases ?
An even pace strategy.
Define an all out pacing strategy?
The race is commenced with an all-out stating strategy with an all-out effort provided over the entirety of the race.
For Events lasting up to 20km what has been shown to be an effect intervention to include pre race to enhance performance ?
Caffeine ingestion has been shown to improve performance by increasing race pace in the middle stages of the race.
Caffeine AND Carbohydrate gum’s have both been found to improve the performance in the latter stages of a race, but these can be taken prior and during.
What is the best pacing strategy for events lasting 1-5 minutes ?
An all out or fast start strategy for the first 15 seconds enhances performance more than an even pace stratagy.
