Inside the long-awaited return of Jon Jones and his quest for heavyweight glory

ALBUQUERQUE, N.M. — JON JONES was giddy entering the Zia Strength Systems gym one afternoon last summer. Jones could not wait to tell Jordan Chavez, his strength and conditioning coach, the good news.

Jones had fought the entirety of his accolade-filled career at light heavyweight — 205 pounds. Before cutting to that weight for competition, the man regarded by many as the greatest MMA fighter ever, walked around at about 230.

On that day,…