Relationship between the sensorimotor cortex and increased heart rate during preparation for maximal voluntary handgrip exercise: A NIRS study

Abstract

  The present study investigated cortical oxygenation in the sensorimotor cortex (SMC) and the concomitant cardiovascular responses during preparation period either followed by maximal voluntary handgrip exercise (Ex) or no exercise (Con) in 13 healthy subjects. We measured levels of oxygenated hemoglobin (oxyHb), deoxygenated hemoglobin (deoxyHb) and total hemoglobin (totalHb) in the SMC by near-infrared spectroscopy and simultaneously recorded heart rate (HR). During 30 seconds before the exercise in Ex, the oxyHb and totalHb in the Premotor cortex (PMC) were significantly higher than those in Con, and deoxyHb was lower than that in Con. These changes in Ex indicated a significant increase in regional cerebral blood flow resulting from neuronal activation in the PMC. In accord with the cerebral changes, HR was elevated significantly in Ex but not in Con. These results suggested that the increases in HR in Ex were coupled with the cortical activation in the PMC resulting from high intensity exercise preparation.