Compressional or primary body waves are body waves that can travel through air, liquid, and solid material. They are body waves that travels through the interior of a body e.g Earth's inner layer. The primary body wave is the fastest to arrive at a location and eventually compresses and expands material in the same direction it travels.
Some of the skateboarder’s stored chemical energy is being used to fuel muscle movement. This movement would also involve a release of thermal energy by the skateboarder.