Drysdale, who won a gold medal for New Zealand in rowing, told The New Zealand Herald that he was walking through the The New Zealand Herald Tongariro Crossing with fellow rowers Lassi Karonen of Sweden and Kim Crow from Australia, when they came upon the injured man.
"We went up [Mount] Ngauruhoe and came across a group of about eight backpackers," Drysdale said. "One of the guys had fallen and had injured his back and had cuts on his arms."
Drysdale, 34, alerted authorities and a rescue helicopter was dispatched.
"We stayed with him until the rescue chopper came and rescued him," Drysdale said.
Greenlea Rescue Helicopter pilot Nat Every said the hiker was transported down a recovery line; "with back injuries and significant grazing to much of his body".