An article of footwear includes an upper member and a sole structure, with a sensor system connected to the sole structure. The sensor system includes a plurality of sensors that are configured for detecting forces exerted by a user's foot on the sensor. Each sensor includes two electrodes that are in communication with a force sensitive resistive material. Additionally, the sensor system may be provided on an insert that may form a sole member of the article of footwear. The insert may include an airflow system that includes one or more air chambers in communication with one or more air reservoirs through air passages extending therebetween. The insert may also have a multi-layered structure, with the airflow system provided between the layers.