LONDON (Reuters) - He can be unassuming and sometimes grumpy, but Glen Mills's Jamaican athletes call him the messiah of sprint coaching and the world is finding out why.
Charges of the 62-year-old coach, including world 100 and 200 metres record holder Usain Bolt and world champion Yohan Blake, have won five of the six medals in the men's sprints at the London Olympics.
"There's times when you want to doubt yourself, but coach is always there to say listen â€کDon't worry I know what I can do to make you run faster and what you need to do to do faster so don't worry'," said Bolt after becoming the first man to retain both the Olympic 100 and 200 metres titles.
"So he's really done a great number on all out us as athletes and he's really pushed us to our limit."
A coach since he was a teenager, Mills witnessed Bolt and Blake claim gold and silver in the 100 metres, then watched on Thursday as his Racers Track Club members incredibly swept the 200 metres with young Warren Weir joining his more famous team mates on the podium.
"What makes it special is that we are all from the same camp, so you know coach Mills is the God of track and field," Blake said.
Bolt credited Mills for bringing him back into winning shape just five weeks after losing twice to Blake at Jamaica's Olympic trials.
"From the start to the finish Glen Mills has been there, he's really worked hard," said Bolt who began working with Mills after the 2004 Athens Olympics.
"There've been times when I doubted myself because of injury and he said â€کDon't worry I know what it takes and know what I can do to make you get back on track."
Mills has been coaching for 47 years, 22 as Jamaica's head coach until 2009 during which the Caribbean island amassed 71 world and 33 Olympic athletics medals.
"I have made track and field a major part of my existence and I work at it for long hours," Mills told Reuters earlier this year in Kingston, Jamaica.
"Maybe I have a talent to coach in a manner that brings results," said Mills, who guided Kim Collins of St Kitts & Nevis to the world 100 metres title in Paris in 2003 long before the emergence of Bolt.
"My knowledge is not exclusive as I believe that other people have similar information. We all get it from the same research, the same scientific data, but maybe I can use it better than most."
His coaching techniques have evolved massively since attaining his diploma in sprinting from the International Olympic Committee Centre in Mexico in the 1970s.
"You gain experience and as you do so, you gain knowledge because you run (training) programmes, develop different people and that expands your experience," said Mills, who coached Jamaica's Raymond Stewart to sixth place in the 1984 Olympics 100 metres final.
His Jamaican team also won a silver in the 4x100 relay in Los Angeles 28 years ago.
"I'm constantly seeking knowledge, whether it's in books, on the Internet or even talking to other practitioners," said Mills who began coaching at Camperdown High school at age 15 years old and founded the Racers Track Club in the 1980s.
"I've learnt a lot from the doctors I associate with as it relates to the function of the human body and the different aspects and effects of training on the human body and so on."
While Bolt, Blake and Weir young enough to seek more global medals, Mills said he was unsure how much longer he would continue coaching.
"It can't be as long as what has gone already," he said. "What I do know is that anytime I don't have that zest, then it's time to pack up."
(Editing by Gene Cherry and Ed Osmond)