Nottinghamshire-based Furniss, who has been working in elite swimming for the past 40 years and took charge of the Team GB squad after London 2012, said Peaty’s feats in the pool over the past decade have been “amazing” and “unbelievable”.
He has an Olympic 4x100m mixed medley gold medal to go with his two in the 100m breaststroke, an event that he has claimed nine world, European and Commonwealth Games titles in since 2014.
He was the first and remains the only man to swim 100m breaststroke in under 57 seconds.
“He has taken the event, in world terms, to another level. His world record, no-one ever thought people could swim that fast,” Furniss said.
“There is a lot of pressure on him and he has had a tough time, he will be the first to admit that. But he has done a great job to get back and he’s certainly not a quitter – he is a fighter.”
During his mental health struggles in recent years, Peaty said “a gold medal is the coldest thing you wear” and that the multitude of accolades he has amassed – which includes eight World Championship gold medals, 17 European titles and four golds at the Commonwealth Games – were no way to solve his problems.
But gold in Paris, said Furniss, would go beyond having just another precious metal draped around his neck.
“Adam Peaty wouldn’t be swimming if he didn’t think he could win another gold medal,” Furniss said.
“He is the ultimate competitor and will give it the best shot he has got. When he comes to do a job, he is absolutely driven.
“I will be honest, if you were racing him you wouldn’t want to be next to him. He won’t give you anything, he is gladiatorial. He gives no quarter and expects no quarter.”