Career
In indoor volleyball Keizer started her career in 1996 at Orion Doetinchem. Other teams she played for were Longa Lichtenvoorde and Martinus Amstelveen. From 1997 until 2002, she was part of the Dutch national youth teams in her age-range.
She started her international beach volleyball career in 2002 at the age of 17.
At the European under 18 Championships they reached the final as well, but this one was lost, resulting in a silver medal. In no-time they were among the best teams in the Netherlands.
They even became Dutch champions, breaking the run of Rebekka Kadijk who was teaming up with Marrit Leenstra at that time. After the 2004 Summer Olympics Kadijk/Leenstra decided to split up.
At the 2012 Summer Olympics, Keizer teamed with Marleen van Iersel.
They qualified from the group stages, but were defeated in the first knockout round by eventual champions, Misty May-Treanor and Kerri Walsh Jennings.