Grass skiing, skiing on grass, is a method for training for alpine skiing. Both grass skiing and alpine skiing have become established as sports in their own right. The skis used for grass skiing are short with rolling treads or wheels. These skis are attached to the skiers' boots. Depending on the skill of the grass skier, high speeds and jumps can be navigated. Grass skiing was invented by Josef Kaiser in Germany in 1963. It was created initially as a training method for skiers before the winter season.