Training partially reverses skeletal muscle metabolic abnormalities during exercise in heart failure.
Using 31P-magnetic resonance spectroscopy during and after exercise, we studied whether forearm metabolic responses to exercise were improved by 1 mo of training in 10 males with heart failure. In the control (untrained) arm, there were no changes in any of the measured variables. In the trained arm, maximal voluntary contraction increased 6% (P = 0.05). During incremental exercise, duration increased 19% (P < 0.05) and submaximal responses improved for pH (6.78 +/- 0.13 pretraining vs. 6.85 +/- 0.17 posttraining; P < 0.01) and PCr/(PCr+Pi) (where PCr is phosphocreatine; 0.48 +/- 0.09 pretraining vs. 0.52 +/- 0.07 posttraining; P < 0.01). The PCr resynthesis rate increased by 48% (P < 0.01), and estimated effective maximal rate of mitochondrial ATP synthesis increased by 37% (P < 0.05). Endurance exercise duration increased by 67% (P < 0.01), and submaximal levels of PCr/(PCr+Pi) (P < 0.05) and pH (P = 0.07) improved. The PCr resynthesis rate (P < 0.01) and the effective maximal rate of mitochondrial ATP synthesis (P < 0.05) also improved. These findings document that impaired oxidative capacity of skeletal muscle can be improved by local muscle training in heart failure, which is compatible with the hypothesis that a part of the abnormality present in heart failure may be due to inactivity.
Stratton
J R
JR
Department of Medicine, Seattle Veterans Affairs Medical Center, Seattle, Washington.
Dunn
J F
JF
Adamopoulos
S
S
Kemp
G J
GJ
Coats
A J
AJ
Rajagopalan
B
B
D000255:Adenosine Triphosphate / Q000096:biosynthesis / Q000378:metabolism; D000328:Adult; D000368:Aged; D005542:Forearm / Q000502:physiology; D006333:Heart Failure / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D009132:Muscles / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology
D010725:Phosphocreatine; D000255:Adenosine Triphosphate