Complex sentence: Stan took first place in the 600-yard run at the NCAA Indoor Championships in 1974 and 1975; during the 1975 indoor season, Vinson established world records at 500-yards and 500-meters.
Split into simpler sentences: Stan took first place in the 600-yard run at the NCAA Indoor Championships in 1974 and 1975. During the 1975 indoor season, Vinson established world records at 500-yards and 500-meters.