Applying science to perfromance Flashcards
Define endurance
the capacity to sustain a given speed or work rate for the longest possible time
In endurance sports where is most of the energy derived from ?
Aerobic oxidative metabolism
What limits a middle distance runners performance
The ability to tolerate metabolic acidosis
What limits long distance events ?
Availability of metabolic substrates and ability to regulate core body temperature
What physiological factors limit endurance performance ?
Vo2 max
Running economy
vo2 Kinetics
Lactate accumulation in muscles and blood
What is an international male distance runners vo2 max ?
70-85ml.kg.min
How do we asses endurance runners vo2 max ?
Incremental treadmill test to exhaustion (Constant speed, elevation 1% each minute)
What are the important determinants of vo2 max?
Q
Total blood volume
Blood haemoglobin concentration
What is running economy ?
The oxygen cost (ml.kg.min-1) of running at a certain speed
What does good running economy result in ?
utilisation of a lower % of the athlete’s VO2 max while running at that speed (reduced use of muscle glycogen and lactate accumulation)
How do we asses running economy ?
Measure over the range of speeds which an athlete may habitually perform their continuous endurance training
VO2 must be measured in ‘steady state’
Stage durations in treadmill tests must be minimum 3 minutes in duration
Treadmill gradient set to 1% (Compensates for lack of air resistance in lab, so energy cost of running is equivalent to that when running outdoors on the road
When does Lactate threshold typically occur ?
50-70% of vo2 max
How long can exercise be sustained for at lactate threshold?
> 2 hours with blood [lactate] elevated but not accumulating over time
What can improvements in endurance fitness be characterised by ?
rightward shift in the blood [lactate] running speed relationship (less accumulation for a given running speed)
How can we asses LT and LTP
Submax, increase speed 1km/h every 3 minutes
What is critical power ?
Hyperbolic relationship between running speed and time to fatigue
Where does critical power fall on the exercise intensity scale ?
Hard and severe
What is o2 kinetics ?
The rate at which VO2 rises following the onset of exercise to meet the anticipated ‘steady state’ demand
What is an adaptation of endurance training ?
Increased capacity to oxidise fat, allowing some sparing of the limited glycogen reserves
What calculation can be used to predict marathon running speed ?
VO2max x %VO2max at lactate threshold x running economy
If an athlete is well trained what can be used to cause further adaptations ?
Blood flow restriction
What does blood flow restriction involve ?
Application of an inflatable cuff around a limb (proximal to the muscles being trained)
• Limits blood delivery to and from contracting muscle
