Dia 1

1
Does the calculated maximal oxygen uptake reflect
the measured maximal oxygen uptake
correctly? P.J.A.M. van Ooij, M.D., A.
Houtkooper bc, R.A. van Hulst, M.D. PhD Diving
Medical Centre, Royal Netherlands Navy, Den
Helder, the Netherlands Pjam.v.ooij.01_at_mindef.nl
Introduction The European Diving Technology
Committee (EDTC) advises, as part of the annual
examination of professional divers, to measure
the maximal oxygen uptake (VO2-max) during
exercise1. This is best done by direct
measurements of the VO2-max. Alternatively the
VO2-max can be calculated by using the formula
of Jones2 or the formula of the American College
of Sports Medicine (ACSM)3 . Our purpose was to
find out whether these formulas calculate the
VO2-max correctly in our population.
Methods At our centre we measure directly the
VO2-max during a maximal exercise test by using
an Oxycon Alfa and a Oxycon Pro device (Viasys
Healthcare Inc). For this study we collect the
results of the maximal exercise tests from our
database from the year 2004 till 2007, which
includes a total of 2499 exercise tests (96
male, 4 female). We compared the measured
VO2-max with the VO2-max as calculated by both
formulas. For practical reasons we reset the
results from the formula of Jones to liter
O2/minute instead of milliliter
O2/minute. Statistical analysis because all the
datasets had a non-normal distribution, the
differences between the measured- and the
calculated VO2-max were assessed by Wilcoxon
Mann-Whitney (W) test. A probability lower than
5 was assumed as threshold to reject the null
hypothesis (no differences between the measured
and calculated values). Results For the
statistic summary of the measured and calculated
VO2-max see table1 and figure 1 and 2. We found
significant differences between the measured
VO2-max and the VO2-max as calculated by either
the formula of Jones (Plt0,01) or the ACSM-formula
(plt0,01). Both formulas calculated a higher
VO2-max than was measured.
fig 1 Measured vs Jones Table
1 Summary of statistics fig 2 Measured vs
ACSM
Conclusion Direct measurement of the VO2-max is
the international accepted standard in exercise
physiology. Indirect measurement may overestimate
the fitness of the diver. If indirect measurement
is used in general practice, Jones formula will
predict the VO2-max most accurately.
Foot-note 1 Wendling, J. Elliott D., Nome,
T. Medical assessment of working divers.
Hyperbaric Editions 2004. 183-186. 2 VO2-max (ml
O2/min) 3,5weight (kg) 10,98Wmax
(watt) 3 VO2-max (ml O2/kg.min) 10,8Wmax
(watt)/weight (kg) 7