StretchArms: Promoting Stretching Exercise with a Smartwatch

A smartwatch is a wearable computer equipped with sensors. It can be used to provide fitness- or healthcare-related functionalities. This article presents three versions of a smartwatch application for prompting a user to stretch during the user’s daily life. The first version just reminds periodically the user that it is time to stretch and then guides the stretching motion. In contrast, the second version evaluates how correctly the stretching motion is made and provides success/fail feedback for the user. The third version adds gamification elements to the second version. With these three versions, an elaborate user study was performed with 42 participants. The results show that the reminders were effective in relaxing the mental/muscular tension of the users and the motion evaluation feedback encouraged the users to stretch more. In contrast, the effectiveness of gamification was not proven. This is the first study to prompt stretching exercise and evaluate it with a smartwatch. It can help develop effective healthcare applications on wearable devices.