A physical activity consumption amount calculation unit calculates the consumption amount of physical activity, which is the amount of physical activity consumed by a subject, from biological information acquired by a biological information acquisition unit. A recovery amount calculation unit calculates the amount of recovery, which is the amount of physical activity recovered by the subject, from the biological information acquired by the biological information acquisition unit. A retained physical activity amount calculation unit calculates the amount of retained physical activity, which is the amount of physical activity retained by the subject, from the reference amount of physical activity set by the reference physical activity amount setting unit, the consumption amount of physical activity calculated by the physical activity consumption amount calculation unit, and the amount of recovery calculated by the recovery amount calculation unit. Therefore, the amount of physical activity retained by the subject can be calculated instantaneously.