No one's going to sign up for a triathalon or long road race without training (except for Barney on "How I Met Your Mother," but that's OK because he's Doogie Howser and, you know, not real). But as triathletes watch their sport increase in popularity, there's also an increase in notoriety, injuries and, as the South Shore realized on Sunday, death. A 38-year-old man died Sunday as he competed in Cohassett's inaugural triathalon. The man......