Effects of specific warm-up at various intensities on energy metabolism during subsequent exercise

Background. To investigate the effects of specific warm-up at various inten sities on energy metabolism during subsequent intense exercise. Methods. Experimental design: specific warm-up was consisted of 3 sets of w rist flexions for 5 min, with each set followed by a 3-min rest. The intens ity of specific warm-up was set at 20%, 30% or 40% of maximal voluntary con traction (MVC). The subjects then performed a set of wrist flexions at 60% MVC for 4 min as the criterion exercise, For the control experiment, criter ion exercise was done without specific warm-up. Participants: Five healthy volunteers. Measurements: using phosphorus-31 magnetic resonance spectrosco py, spectra were obtained from the wrist flexor muscles to determine the ra tio of inorganic phosphate to phosphocreatine (Pi/PCr) and intracellular pH . Results. The Pi/PCr during the criterion exercise after specific warm-up at any intensity was not significantly different from that without specific w arm-up. The intracellular pH during the criterion exercise after specific w arm-up at 30% or 40% MVC was significantly higher than that without specifi c warm-up. Conclusions. These results indicate that mild warm-up exercise could inhibi t the development of intracellular acidosis during subsequent intense exerc ise.