It appears masturbating isn't the only form of unique training Tyson Fury is doing ahead of his rematch with Deontay Wilder.
The former WBO heavyweight champion has revealed yet another unorthodox preparation technique, telling media on a conference call he had been performing cunnilingus in order to strengthen his jaw.
Fury made the comment after being asked if he had been working to make his chin 'more impregnable' after being knocked down when the two fought to a draw in 2018.
"So yeah, I've been strengthening the old jaw up."
It's the latest x-rated training method to find its way into Fury's training regime. In January, he told HoopJab he had been masturbating up to seven times a day to keep his testosterone levels up.
"I've got to keep active and my testosterone flowing for this fight. I don't want the levels to go down," he said.
Deontay Wilder and Tyson Fury will square off next weekend in Las Vegas. Photo / Getty Images
Fury and Wilder fought to a split draw in December 2018 in a fight that saw both men have their moments. Fury was dropped twice during the fight, but out-landed Wilder 84-71, connecting on about 26 per cent of the punches he threw.
The fight was scored very differently by the three judges, with scores of 115-111 Wilder, 114-112 Fury, and 113-113. The draw saw Wilder retain his WBC heavyweight title.
The two will square off again on Sunday February 23 (NZ time) at the MGM Grand Garden Arena in Las Vegas.
Both fighters have had two bouts since their last encounter. Wilder won both his fights by stoppage, while Fury won via stoppage and decision.
The draw in 2018 is the only blemish on each of the fighters' resumes, with Wilder winning all 42 of his other professional bouts (41 KO) and Fury his other 29 bouts (20 KO).