Complex sentence: In 2015, his rise continued, breaking the world record for 100 metre breaststroke at the British Championships and World Trials by almost half a second with a time of 57.92 seconds, to become the first man under 58 seconds for the event.
Split into simpler sentences: In 2015, his rise continued, breaking the world record for 100 metre breaststroke at the British Championships and World Trials by almost half a second. His time of 57.92 seconds made him the first man to go under 58 seconds for the event.