Even as a young lad, Martijn wanted to be a professional BMX rider when he grew up. A huge fan of Robert de Wilde and Robert Sprokholt, he began to act out his hobby at the age of three. No surprise (a) that he won the Dutch Championships in the 4 and under boys category and (b) that, in 1995, he entered his first European Championships in 7 boys and finished 2nd. He kept getting 2nd place each year – until 1999 when he won his first European title in 11 boys and in 12 and under cruiser. Then in 1996, Martijn entered his first World Championships in England, where he also finished 2nd. In 1999, he won his first World Championships. He turned professional rider in 2006.