抄録
To investigate the splitting of the inorganic phosphate (Pi) peak during exercise, a time-resolved ^31phosphbrus nuclear magnetic resonance spectroscopy (^31P-MRS) technique was used. Eight long-distance runners performed knee flexion exercise in the prone position inside a 2.1-T magnet, with the surface coil for ^31P-MRS being placed on the biceps femoris muscle. After a 4-min warm-up without loading, the exercise intensity was increase to 60% max. ^31P-MRS data were collected at 12 scans per spectrum every 5 seconds. During warming-up exercise and exercise without warming-up the area of Pi peak increased, creatine phosphate (PCr) decreased, the inorganic phosphate/phosphocreatine ratio (Pi/PCr ratio) increased. The Pi/PCr ratio when the Pi splitting was observed during exercise without warm-up was significantly smaller than that during exercise with warm-up. It was implied that Pi splitting is observed when anaerobic glycolysis is activated.
