A2 Sport and PE

V02MAX Testing and OBLA

Learning Outcomes

• Define Vo2max and OBLA

• Explain the physiological affects on Vo2 MAX

• Relate Vo2MAX to OBLA

• Explain the effects of your training on your own V02MAX scores and your own OBLA.

Vo2 MAX• What is it?

• The amount of oxygen the body can take in and use in one minute.

• MASSIVELY IMPORTANT

• Why?

• Gives an accurate idea of how well a person’s body can perform over a long period of time OR how intense they will be able to perform.

Vo2 MAX

• Average for A Level students:

• Male: 45-55ml kg -1

• Female: 35-44ml kg-1

World Records

• Men – 96 ml kg-1• Norwegian Cross

Country Skiier• Women – 78.6 ml

kg-1• 1984 Olympic

Marathon Champion

Factors Affecting Vo2Max• What affects this?• The amount of capillaries around the lungs and the

working muscles• The amount of haemoglobin in the blood• The type of training (or otherwise) the muscle has

been through.• Gender – women have smaller left ventricles, lower

stroke volumes, lower haemoglobin levels and lower respiratory levels.

• Age – the older you get the lower your heart rate becomes (5-7 beats lost per decade), lower vital capacity and lower blood pressure.

Training Effects

• Regular aerobic training raises V02 Max, due to:

• Increased cardiac output and stroke volume• Increased haemoglobin• Increased glycogen stores• Increased OBLA (more on that in a minute)• Reduced body fat (therefore less oxygen

being used for the energy systems)

Training Effects

• Why do these effects occur with aerobic training?

• You’re forcing the body to either find more oxygen, or create ways of getting the oxygen from the lungs to the working muscle.

• Various methods of achieving this…..

Evaluating V02Max

• Almost all tests are MAXIMAL……

• Full pelt, to the point of exhaustion.

• Douglas bag• Multistage fitness test

(bleep test)• Harvard step test• Cooper 12 minute run

OBLA• Stands for…….?• Onset of Blood

Lactate Accumulation

• And this means…..?• The point at which

the muscle can no longer get rid of the lactic acid and it begins to pool in the blood

OBLA

• Normal amount of lactate in the blood:• 1 ml/kg• OBLA occurs at:• 4 ml/kg• Once the blood contains four times as

much lactic acid as normal, it can no longer operate the energy systems effectively and the body begins to slow and eventually fail.

OBLA and Vo2MAX• Average person reaches OBLA at• 40% of Vo2MAX• Meaning that the average person can only

work at less than half their maximum ability before fatigue sets in.

• Endurance athlete reaches OBLA at• 85% of Vo2MAX• The endurance trained athlete can work at

almost maximum before fatigue set in.

OBLA• The affects of OBLA:• Stops oxygen being collected by the haemoglobin• Causes the pH of the blood to rise causing pain in

the working muscle• Also decreases the amount of oxygen that can be

used for phosphorylation.• Will eventually lead to the muscle failing – you

collapse!

OBLA

• If the intensity of the activity increases, the performer will have to switch from using aerobic capability to anaerobic, which results in…….?

• Increased lactate build up.

Factors Affecting OBLA

• Intensity of exercise – compare short burst, high intensity to long distance, steady state.

• Muscle fibre type being used – more on that later.

• The ability of the body to remove and oxidise lactate.

• Training adaptations to exercise.

Questions

• It is important as a games player to have a good V02Max. What is meant by the term V02Max? (2 marks)

• Suggest five structural and/or physiological causes of the difference in V02max between a trained and an untrained individual. (5 marks)

• Describe and explain how lactate threshold varies as fitness improves. (3 marks)

Learning Outcomes

• Define Vo2max and OBLA

• Explain the physiological affects on Vo2 MAX

• Relate Vo2MAX to OBLA

• Explain the effects of your training on your own V02MAX scores and your own OBLA.