Webinar for USA Cycling Coaching Education program.

1. VO2max:
what does it really mean?
Andrew R. Coggan, Ph.D.
Cardiovascular Imaging Laboratory
Washington University School of Medicine
St. Louis, MO 63110

2. Maximal O2 uptake (VO2max)
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What is it?
Why is it important?
What determines it?
How do you train it?
How do you measure it?

3. VO2max – what is it?

4. VO2max – what is it?
• The highest rate of whole-body oxygen uptake
(VO2) achievable during exercise that utilizes a
large muscle mass (e.g., running).

5. Plateau in VO2 with increasing
exercise intensity

6. VO2max – what is it?
• The highest rate of whole-body oxygen uptake
(VO2) achievable during exercise that utilizes a
large muscle mass (e.g., running).
• An intrinsic biological characteristic of an
individual at any particular point in time.

7. VO2max – why is it important?

8. VO2max – why is it important?
• VO2max is the best overall measure of
cardiovascular fitness and sets the upper limit to
the production of energy (ATP) via aerobic
metabolism (i.e., mitochondrial respiration). As
such, having an adequately high VO2max is a
necessary but not a sufficient condition to be an
elite endurance athlete.

9. VO2max in different
groups of athletes

10. VO2max – what determines it?

11. VO2max – what determines it?
• While there are numerous steps involved in the
transport of the O2 from the atmosphere to the
mitochondria where it is utilized, the primary
limiting factor to VO2max is maximal cardiac
output, and in particular, maximal stroke volume.

12. The cardiovascular Fick equation:
• The Fick equation represents the relationship of the .
.
body’s oxygen consumption (VO2) to cardiac output (Q)
and the arterial-mixed venous oxygen difference (a-vO2
.
diff):
.
.
VO2 = Q x a-vO2 diff
.
or
VO2 = HR x SV x a-vO2 diff
During maximal exercise:
.
VO2max = HRmax x SVmax x a-vO2 diffmax

13. Relationship between VO2max and
maximal cardiac output

14. Stroke volumes (SV) for different
states of training
Subjects
SV @ rest (ml)
SV @ max (ml)
Untrained
50-70
80-110
Trained
70-90
110-150
Highly trained
90-110
150-220

15. VO2max – how do you train it?

16. Role of genetics in determining
baseline VO2max

17. Role of genetics in determining
trainability of VO2max
From D. Prud'homme et al., 1984, “Sensitivity of maximal aerobic power to training is genotype-dependent,”
Medicine and Science in Sports and Exercise 16(5): 489-493. Copyright 1984 by American College of Sports
Medicine. Adapted by permission.

18. Role of genetics in determining
trainability of VO2max
.
Adapted, by permission, from C. Bouchard et al., 1999, “Familial aggregation of VO 2max response to exercise
training: Results from HERITAGE Family Study,” Journal of Applied Physiology 87: 1003-1008.

19. VO2max – how do you train it?
• At least/especially in untrained persons,
“ordinary” endurance exercise training, if of
sufficient intensity (i.e., >50-60% of VO2max),
frequency, and duration will lead to an
improvement in VO2max, but
• As an individual becomes more fit, it becomes
progressively harder and harder to elicit further
improvement, necessitating that the exercise
intensity be increased if any further gains are to
be achieved.

20. VO2max – how much
can it be improved?
Training program:
• Running “all-out” for 40 min/d,
3 d/wk.
• Cycling (on an ergometer) 6 x
5 min on, 2 min off, 3 d/wk.
Power during intervals set so
that subject achieved VO2max
during each effort.
Hickson, Bomze, and Holloszy. J Appl Physiol 1977; 42:372-376.

21. Changes in VO2max over time in a
world class team pursuit cyclist
Jeukendrup AE, Craig NP, Hawley JA. J Sci Med Sport 2000; 3:414-433.

22. VO2max – how do you
measure it?

23. VO2max – how do you measure it?
• By using a “metabolic cart” (gas analyzers, flow
measuring device) to quantify respiratory gas
exchange (VO2, CO2 production (VCO2)) across
the lungs/at the mouth during an incremental
exercise test.

24. Subject performing VO2max test

25. Characteristics of “ideal” VO2max test
• Total duration 8-12 min
• Stages typically 1-3 min in length
• Exercise intensity increased by <5-8% of VO2max per
stage, at least towards end of test
• For athletes, sports-specific mode of exercise:
∴ cyclists → cycling

26. Calculation of VO2, VCO2, and RER
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VO2 = rate of O2 uptake (L/min or mL/min/kg).
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VCO2 = rate of CO2 release (L/min or mL/min/kg).
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VO2 = (VI • FIO2) - (VE • FEO2)
.
.
..
VCO2 = (VE • FECO2) - (VI • FICO2)
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RER = VCO2 / VO2
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Where VE = expired ventilation; VI = inspired ventilation;
FIO2 = fraction of oxygen inspired; FICO2 = fraction of carbon
dioxide inspired; FEO2 = fraction of oxygen expired; and
FECO2 = fraction of carbon dioxide expired.

27. Criteria for identification of VO2max
• Absolute or relative plateau in VO2 despite increase in
O2 demand (e.g., <150 mL/min or <1.5 mL/min/kg
increase between stages)
• RER > 1.10
• Heart rate w/in 10 beats/min of age-predicted
maximum
• Blood lactate concentration > 8 mmol/L
• Volitional fatigue is not evidence that VO2max has
been achieved!

28. Common problems or errors in
determining VO2max
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Failure to achieve a clear plateau
Inappropriate “cherry picking” of data
Inaccurate or miscalibrated gas analyzers
Inaccurate measurement of ventilation

29. Example of a good VO2max test

30. Power-VO2 relationship

31. Example of a VO2peak test

32. Inappropriate “cherry picking” of data

33. Inaccurate or miscalibrated gas
analyzer

34. Power-VO2 relationship

35. Inaccurate measurement of
ventilation

36. Power-VO2 relationship

37. Key Points
Maximal O2 uptake:
 is the highest rate of whole-body oxygen uptake (VO2)
achievable during exercise that utilizes a large muscle mass
(e.g., running).
 is the best overall measure of cardiovascular fitness.
 sets the upper limit to the production of energy (ATP) via
aerobic metabolism (i.e., mitochondrial respiration), such that
 having an adequately high VO2max is a necessary but not a
sufficient condition to be an elite endurance athlete.

38. Key Points (con’t)
Maximal O2 uptake:
 is determined approximately equally by both genetic
and environmental factors (e.g., training).
 can be readily measured using a metabolic cart