In 2000, de Maar won some criteriums in the Netherlands, and signed a youth contract for two years for Rabobank Beloften.

In those years, he won some races, and in 2006 he became a member of the professional division of Rabobank.

With 9 kilometres (5.6 mi) left, he hit the tarmac with two other riders after taking a corner too wide.

He rode away solo 6.5 kilometres (4.0 mi) from the finish, and crossed the line with an advantage of 15 seconds on the chasers.

[5] In September 2014 it was announced that de Maar would join the new Team Roompot squad for 2015.