Brian Halford, 38, was one of seven firefighters injured in the blast which ripped apart the Icepak Coolstore in suburban Tamahere on April 5, claiming the life of Senior Station Officer Derek Lovell.
Mr Halford suffered head injuries in the blast and was buried under the coolstore's rubble, injuring his back, shoulder and neck.
While he still has trouble eating, talking and remembering things, he plans to compete in the Taupo Ironman next month.
The event involves a 3.8km swim, 180km bike ride and 42km run to finish.
Mr Halford, who was in hospital for two weeks, stunned medical staff when he went on to compete in the Rotorua Marathon soon after the fire and Round the Bridges in Hamilton in November.
The biggest part of his recovery was regaining his memory, he told The Waikato Times.
He lost his memory of the six to eight months after the fire and also a lot of the last five years.
Eating, breathing, swimming and even talking for long periods ignited throbbing in his face.
Mr Halford said it would be a while yet before he went back to work.
