Tuhia he haere tonu mo tenei whitianga - I timata a Thijs i te atamira o te ao i te 2002 European Aquatics Championships
i roto i te Berlin. Ko te whakatutukitanga nui a Van Valkengoed ko te wikitoria i te mētara parahi i te 200 m breaststroke i te European Short Course Swimming Championships 2003 i Dublin, Ireland. I te timatanga o taua marama i tohu ia i a ia ano mo te 2004 Summer Olympics me nga rekoata a motu i te 100 m me te 200 m breaststroke. I nga Orimipia i whakakorea ia i nga hawhe whakamutunga o te 100 m breaststroke, me nga wera o te 200 m breaststroke.