Bij een inspanningstest worden aan de hand van een fietsproef een aantal
zaken in kaart gebracht:
hartslag in rust, maximale inspanning (in Watt), maximale zuurstofopname
en anaerobe drempel.
Zoals al eerder gemeld
(klik hier),
kunnen ME/CVS-patiėnten blijkbaar (op doorzettingsvermogen?)
eenmalig nog een inspanning leveren die redelijk in de buurt komt van gezonde mensen,
maar bij een tweede inspanningstest wordt de tol die de eerste inspanning kost, terugbetaald.
Using Serial Cardiopulmonary Exercise Tests
to Support a Diagnosis of Chronic Fatigue Syndrome
Medicine & Science in Sports & Exercise:
Volume 38(5) Supplement May 2006 p S85
VanNess JM, Snell CR, Stevens SR, Bateman L, Keller BA.
Reduced functional capacity and post-exertional malaise following physical activity
are hallmark symptoms of Chronic Fatigue Syndrome (CFS). That these symptoms are often delayed
may explain the equivocal results for clinical cardiopulmonary exercise testing (GXT) with CFS patients.
The reproducibility of VO max in healthy subjects is well documented. This may not be the case with CFS due to
delayed recovery symptoms.
PURPOSE:
To compare results from repeated exercise tests as indicators of post exertional malaise in CFS.
METHODS:
Peak oxygen consumption (VO2peak),
percentage of predicted peak heart rate (HR%), and VO2 at
anaerobic threshold (AT), were compared between six CFS patients and
six
control subjects for two maximal exercise tests separated by 24 hours.
RESULTS:
Multivariate analysis showed no significant differences between control and CFS,
respectively, for test 1: VO2peak (28.4 ± 7.2 ml/kg/min; 26.2 ± 4.9 ml/kg/ min), AT (17.5
± 4.8 ml/kg/min; 15.0 ± 4.9 ml/kg/min) or HR% (87.0 ± 25.4%; 94.8 ± 8.8%).
However, for test 2 the CFS patients achieved significantly lower values
for both VO2peak (28.9 ± 8.0 ml/kg/min; 20.5 ± 1.8 ml/kg/min,
p=0.031) and AT (18.0 ± 5.2 ml/kg/min; 11.0 ± 3.4 ml/kg/min, p= 0.021). HR%
was not significantly different (97.6 ± 27.2%; 87.8 ± 9.3%, p=0.07).
A follow-up classification analysis differentiated between CFS patients and
controls with an overall accuracy of 92%.
CONCLUSION:
In the absence of a second exercise test, the lack of any significant differences for the first test would
appear to suggest no functional impairment in CFS patients. However, the results from the second test indicate
the presence of a CFS related post-exertional malaise. It might be concluded then that
a single exercise test is insufficient to demonstrate functional impairment in CFS patients. A second
test may be necessary to document the atypical recovery response and protracted malaise unique to CFS
©2006 The American College of Sports Medicine
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