Systems and methods for communicating helmet usage information during operation of an activity device are provided. One example aspect of the present disclosure is directed to a system for communicating helmet usage and includes one or more position sensors, one or more activity sensors and one or more computing devices. The one or more position sensors can be configured to be positioned on a helmet, to detect placement of the helmet on a user's head and to transmit signals indicative of such placement. The one or more activity sensors can be configured to be positioned on an activity device, to detect operational indicators relative to the usage of the activity device and to transmit signals indicative of such operational indicators. The one or more computing devices can be configured to: receive signals from the one or more position sensors and the one or more activity sensors, determine whether the activity device is likely engaged in one or more given activities, and generate/communicate at least one helmet usage indication signal to a user of the activity device and/or to a third party via a remote device.