Windsurfing and skiing 

     Skiing and windsurfing are complementary sports, useful to both types of athletes for maintaining the level of their fitness in low season.

     With only the first steps, a beginner in skiing learns to keep his balance overcoming external forces, gravity and centrifugal force, which depend on the position of the body to the ground, speed and turning radius.

     A beginner in windsurfing also first learns how to keep his balance towards external forces, in this case the wind. The speed of wind creates the moment of force the same way as gravity does in skiing...