A system assesses activity of a sportsman engaged in board sports. At least one sensor detects movement of the sportsman, and a processor processes data from the sensor to assess activity of the sportsman. Activity of sportsmen engaged in human powered sports is compared. A plurality of activity sensing units is associated with the sportsman. Each of the units (a) attach to one of either the sportsman or to a human powered vehicle ridden by the sportsman, and (b) wirelessly communicate activity to a remote location. The activity comprising one or more of airtime, speed, drop distance, power and energy absorbed. A database, accessible by Internet and connected to the remote location, provides access to the activity via the Internet.