Complex sentence: Unable to take part in the 1904 Summer Olympics due to a disease, he competed at the 1906 Summer Olympics, where he took part in the two-days weightlifting competition with both hands.
Split into simpler sentences: Unable to take part in the 1904 Summer Olympics due to a disease, he competed at the 1906 Summer Olympics. He took part in the two-days weightlifting competition with both hands.