Marcos was part of the Spanish team that travelled to the 1996 Summer Paralympics in Atlanta where he competd in the 100m, 200m and long jump. He was also part of the team that travelled to Sydney for the 2000 Summer Paralympics again competing in the 100m and 200m as well as the 4 × 100 m and part of the Spanish silver medal winning 4 × 400 m T46 relay team.