In the sport of mountain biking, a cyclist possesses two forms of potential energy; potential energy stored in muscles from food and potential energy attained from sitting at the top of a hill. Both of which eventually get transferred into kinetic energy.

Lets look at the energy stored in the legs. This energy is transferred to the pedals, which turn the rear wheel, and causes the bike to move. The potential energy stored in the legs is what gets us to the top of inclines, which allows us to experience the second form of potential energy.

At the top of an incline a mountain biker, if at rest, possesses only potential energy. But if he is in motion, then he also possesses mechanical energy. As the biker rides down the hill his potential energy from the incline is depleting and being transferred into kinetic energy. At the bottom of the incline his kinetic energy is at its maximum, and the only potential energy left, is the energy stored in his legs.