Complex sentence: After transferring to athletics, as a T54 athlete, he competed at the 2004 Athens Paralympics in five events and won a silver medal in the Men's 4 x 100m Relay T53-54.
Split into simpler sentences: After transferring to athletics, as a T54 athlete, he competed at the 2004 Athens Paralympics. He competed in five events and won a silver medal in the Men's 4 x 100m Relay T53-54.