An exercise load intensity evaluation device includes a pulse wave detection section which is attached to a subject during exercise and noninvasively detects a peripheral pulse wave. An ejection duration calculation section measures ejection duration from a feature of the pulse wave (dicrotic notch, for example) which reflects the cardiac ejection duration based on the detected pulse wave. The ejection duration measured at each measurement time by the ejection duration calculation section is input to an ejection duration change detection section, and the ejection duration change detection section detects a change in the ejection duration. Exercise load intensity of the subject during exercise is evaluated based on output from the ejection duration change detection section.