Kylie Mantz and her Olympian husband Conner Mantz crushed a marathon together in November. A few weeks later, they learned they were running with a third person.

NEW HAVEN – Conner Mantz knew when he threw in a few surges in the first few miles of Monday’s Faxon Law New Haven 20K and failed to shake Hillary Bor and Isai Rodriguez that it was going to be a fast ...