The active running wheel system in rats is driven by the spontaneous movement of the animal itself to rotate the running wheel. In this configuration, the long-term activity information of the animals in the cage, such as the direction of wheel rotation, number of revolutions, cumulative total travel, etc., can be recorded using an encoder for length measurement. This device consists of a rotating wheel component, a cage, and a rotation direction and speed sensor. The instrument is an experimental tool for studying animal circadian rhythms. Optional food dispensers can also be used for exercise reward experiments.