This document defines Vo2max and OBLA, and explains their relationship and importance for athletes. Vo2max measures the maximum amount of oxygen the body can use during exercise, and is important for endurance. OBLA is the point at which lactic acid builds up in the blood due to insufficient oxygen intake. The document outlines how training increases Vo2max through physiological adaptations, and lowers the intensity at which OBLA occurs. It concludes by relating Vo2max, OBLA and lactate threshold to an individual's fitness level and training.

1. A2 Sport and PE
V02MAX Testing
and OBLA

2. 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.

3. 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.

4. Vo2 MAX
• Average for A
Level students:
• Male: 45-55ml
kg -1
• Female: 35-
44ml kg-1

5. World Records
• Men – 96 ml kg-1
• Norwegian Cross
Country Skiier
• Women – 78.6 ml
kg-1
• 1984 Olympic
Marathon Champion

6. 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.

7. 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)

8. 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…..

9. 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

10. 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

11. 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.

12. 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.

13. 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!

14. 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.

15. 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.

16. 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)

17. 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.