Complex sentence: On 7 September 2014 Mo Farah competed in the Great North Run, a British half marathon, and won the race in a personal best time of 1:00:00, exactly 1 hour.
Split into simpler sentences: On 7 September 2014, Farah competed in the Great North Run, a British half marathon. He won the race in a personal best time of 1:00:00, exactly 1 hour.