Complex sentence: Originally trained in windsurfing, Roman Hagara soon competed against his now team mate Hans-Peter Steinacher, until they decided in 1997 to train for the 2000 Olympics together.
Split into simpler sentences: Originally trained in windsurfing, Roman Hagara initially competed against his now team mate Hans-Peter Steinacher. In these years, the now teammates competed against each other until they decided in 1997 to train fort he 2000 Olympics together.