Favorable responses to acute and chronic exercise in McArdle patients.
OBJECTIVE
This study reports acute exercise responses in a large (N = 46) series of patients with McArdle disease and responses to exercise training in a smaller (n = 9) set of patients.


METHODS
Patients were studied during both incremental and steady-state cycle ergometer exercise, using cardiopulmonary testing, and the patients were compared with age- and gender-matched controls.


METHODS
The study was performed in a university setting (clinical exercise physiology laboratory).


METHODS
The 46 patients showed common features of McArdle disease. They were definitively diagnosed by histochemistry, biochemistry, and/or molecular genetic analysis. The 46 controls were healthy, sedentary individuals.


METHODS
Nine patients were studied before and after an 8-month supervised aerobic exercise training program (including five weekly sessions of walking and/or cycling exercise with a duration no greater than 60 minutes).


METHODS
The main indicators of exercise capacity that we measured were peak power output, peak oxygen uptake (VO2peak), and ventilatory threshold (VT).


RESULTS
Exercise capacity (peak power output, 35% control; VO2peak, 44% control; VT, 66% control) was markedly depressed in the patients. The patients who trained improved peak power output (25%), VO2peak (44%), and VT (27%), with no evidence of negative outcomes from training. Although not achieving normal values, the response to training put the patients into the lower limit of normal controls.


CONCLUSIONS
Under carefully controlled conditions, patients with McArdle disease may perform acute exercise safely, and they may respond favorably to training. This may offer an additional therapeutic option to help normalize the lifestyles of these patients.
Maté-Muñoz
José L
JL
Universidad Europea de Madrid, Madrid, Spain.
Moran
Maria
M
Pérez
Margarita
M
Chamorro-Viña
Carolina
C
Gómez-Gallego
Félix
F
Santiago
Catalina
C
Chicharro
Luis
L
Foster
Carl
C
Nogales-Gadea
Gisela
G
Rubio
Juan C
JC
Andreu
Antoni L
AL
Martín
Miguel A
MA
Arenas
Joaquín
J
Lucia
Alejandro
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001774:Blood Chemical Analysis; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006012:Glycogen Storage Disease Type V; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D010101:Oxygen Consumption / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D013030:Spain