Complex sentence: After the 2005 World Aquatics Championships in Montreal, Canada Olaf decided to leave Spain, and started to train in the Netherlands, first with coach Fedor Hes in Amsterdam, and later on with coach Jacco Verhaeren and reigning Olympic champion Pieter van den Hoogenband in Eindhoven.
Split into simpler sentences: After the 2005 World Aquatics Championships in Montreal, Canada he decided to leave Spain, and started to train in the Netherlands. First with coach Fedor Hes in Amsterdam, later on with coach Jacco Verhaeren and reigning Olympic champion Pieter van den Hoogenband in Eindhoven.