Heavyweight champion  Jon Jones was injured while preparing for his UFC 295 title defense against former titleholder  Stipe Miocic .  ”Bones” tore his pectoral muscle while training last October.   Jones underwent surgery days later and has done physical therapy for months.  It’s been six months since the surgery and Jones has returned to the gym.   “First day back in the gym since my injury, felt amazing,” Jones wrote on Instagram