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
|
