He was 27 years old and at his boxing peak physically and mentally , Ali , 29 , was coming back from a three - year absence but had kept active .
Several factors came together for Frazier in this fight .
Frazier was 27 years old and at Frazier 's boxing peak physically and mentally , Ali , 29 , was coming back from a three - year absence but had kept active .
Several factors came together for Frazier in this fight .