Abstract: An exercise load determination method and an exercise load determination device that can easily and accurately determine whether an exercise load is appropriate or not. An acquisition unit acquires first acetone concentration value being concentration of acetone released from a subject before exercise of the subject and second acetone concentration value being concentration of acetone released from the subject after a specified period of time from an end of the exercise by the subject, a determination unit calculates a comparison value between the first acetone concentration value and the second acetone concentration value, compares the comparison value with a preset threshold, and determines whether an exercise load of the exercise is appropriate for the subject, and an output unit outputs information based on a determination result by the determination unit.