Complex sentence: He then moved to Vancouver in 2007 to attend the University of British Columbia, where he competed with the UBC Thunderbirds, UBC's swimming team, and broke records set by Hayden, a future team member in the relay.
Split into simpler sentences: He then moved to Vancouver in 2007 to attend the University of British Columbia. There, he competed with the Thunderbirds, UBC's swimming team, and broke records set by Hayden, a future team member in the relay.