TY - JOUR 
A1 - Rae, Dale E.
AU - Noakes, Timothy D.
AU - San Juan, Alejandro F.
AU - Pérez Ruiz, Margarita
AU - Nogales-Gadea, Gisela
AU - Ruiz, Jonatan R.
AU - Morán, María
AU - Martín, Miguel Ángel
AU - Andreu, Antoni L.
AU - Arenas, Joaquín
AU - Lucía Mulas, Alejandro
T1 - Excessive skeletal muscle recruitment during strenuous exercise in McArdle patients
Y1 - 2010
SN - 14396327
UR - http://hdl.handle.net/11268/1096
AB - We compared the cardiorespiratory response and muscle recruitment [as determined by electromyography (EMG)] of 37 McArdle patients [19 males, 37.4 ± 2.8 years, body mass index (BMI): 25.1 ± 4.7 kg m(-2)] and 33 healthy controls (18 males, 36.4 ± 10.0 years, BMI: 25.7 ± 3.8 kg m(-2)) during cycle-ergometer exercise (an incremental test to exhaustion and a 12-min submaximal constant workload test). We obtained cardiorespiratory [oxygen uptake and heart rate (HR)] and EMG data (rectus femoris and vastus lateralis muscles). During the incremental test, the patients exhibited the expected hyperkinetic cardiovascular response shown by a marked increase in the slope of the HR:Power relationship (p < 0.001). Throughout the incremental test and at the point of fatigue, the patients produced significantly less power than the controls (peak power output: 67 ± 21 vs. 214 ± 56 watts respectively, p < 0.001), yet they demonstrated significantly higher levels of muscle activity for a given absolute power. During the constant workload test, patients displayed higher levels of EMG activity than the controls during the second half of the test, despite a lower power production (34 ± 13 vs. 94 ± 29 watts respectively, p < 0.001). In conclusion, since the McArdle patients required more motor unit recruitment for a given power output, our data suggest that the state of contractility of their muscles is reduced compared with healthy people. Excessive muscle recruitment for a given load could be one of the mechanisms explaining the exercise intolerance of these patients.
KW - Enfermedad nutricional
KW - Deporte
KW - Tratamiento médico
LA - eng
ER -