Under his watch, the boys in black have become faster, stronger and bigger, the weight of the average lock rising from 113kg to 118kg, and props even more dramatically from 115kg to 124kg. And as everyone knows, they also won their first World Cup in 24 years in 2011.
In his time, Gill has trained 200 All Blacks and never missed a test (there have been 110).
He was absent at only one training session, in his second week on the job, and only then because the team doctor wouldn't let him out of his room.
"She said: 'You're too sick. You can't go near the team,'" he recalls.
Gill regards working with the All Blacks as the ultimate job and says their motivation, talent and intelligence are extraordinary.
But the father of two also gets a buzz out of helping lesser mortals, including primary school children, up-and-coming athletes and Air New Zealand pilots. (In four months this year, he helped 90 pilots at the national carrier shed a combined 560kg.)
GILL is leaner than I expect, and tells me later he weighs 88kg, dropping to 82kg when he is Ironman-ready.
He is also much less the rugby hard man than one would anticipate and unlike many in his world who are prone to speaking in short, sharp sound bites, he is effusive and warm and brilliantly talkative.
That is not to say he is above rugby war rhetoric, calling the World Cup "a job on enemy soil", but he has a gentle manner, is generous with his time, and his blue eyes light up when he talks about his family, wife of 14 years Mel and the "biggest buzz" in his life, daughters Olyvia and Grayce.
Unsurprisingly, as a coach for one of the world's best sports teams, Gill boasts an impeccable CV.
He came to the All Blacks from the Chiefs and the New Zealand Academy of Sport, and has recently been hired by Cycling NZ to help its pursuit teams prepare for the Rio Olympics.
Passionate about cycling, he came close to making the national team as a youngster before his parents moved from West Auckland to Waiheke Island.
"Training was blown out the door."
He has also played rugby and rates his three nine-hour Ironman events as his proudest personal sporting accomplishments, but sport is not where his talent ends.
He is also an associate professor at Auckland University of Technology, contributing to more than 50 research papers and currently supervising eight PhD students.
While his CV speaks volumes about his apt combination of brawn and brains, it is obvious that Gill's personality plays a big part in his All Blacks appeal.
He boasts a phone full of texts from that morning from the likes of Richie McCaw, Dan Carter and Victor Vito, and it is obvious they all want desperately to please him.
"Time heaps better today Gilly," says one. "Must be coming out of the hole."
GILL admits to feeling "under the pump" when we meet.
He has spent the week doing eight-hour training sessions with the new World Cup squad and met with those who failed to make the cut.
"It is a hard fact of the All Blacks," he says. "You actually never get to say goodbye. They just don't come back."
He is also preparing to leave home for the tournament, which includes leaving his daughters, aged 10 and 14.
He says, "the longer I've done it, the harder it's got", and today he will be in London, beginning to exercise the players ahead of their first pool match against Argentina next weekend.
Despite keeping up-to-date with all the latest sports science, Gill's training mantra is to stick to the basics and "keep doing them better than anyone else".
Instinct tends to form the basis of what he and the other coaches do, although tools like GPS can help ensure they have got it right, he adds.
An All Black halfback runs about 10km in a game during the 35 to 40 minutes the ball is in play, half of it jogging and the other half sprinting, so GPS aids in checking training distances and speeds.
And, in the business of improving players' performance, Gill says, team mentality is everything.
FORMER All Black Justin Marshall has called Gill one of the unsung heroes, but Gill says, "I'm just a small part of a massive team".
"And every part of our organisation is so good. And everyone has that same attitude. We wake up every morning - I'm talking all staff - wanting to be the best in the world at our job."
He says he cares deeply for the players and places great importance on building relationships and earning their trust through communication and honesty.
"It's no different to being a parent. You can either just tell your kids to do something, or you can try and teach them about why they're doing it and how to do it, and hopefully they understand the importance so they start doing it by themselves."
He talks repeatedly of players' feelings, but his is not just the language of love and fluffy bunnies. Anyone not fit enough becomes his "pet rat" and he repeats the refrain, "you gotta be able to hurt. You gotta be able to suffer".
Over the years, his relationship with the players has evolved, he says, and now at 40, he is older than anyone on the team.
"Some are young dads so I can put my arm round them and say, 'you're not getting any sleep'... It's a matter of understanding what you could share an interest in."
Fishing and hunting are hobbies he shares with some of the "good Kiwi blokes" on the team, and he also credits similar music tastes and his West Auckland upbringing with giving him cred. "I was a Westie bogan so I can relate to most of them," he says.
GILL went to Massey High School and was the first in his family to go to university, beginning with an honour's degree in physical education at Otago University, followed by a PhD in sports science at Southern Cross University in Australia.
He won a scholarship to Southern Cross, where he met his web designer wife, and says his time across the Tasman cemented his love of sport and wanting to make a career of helping other athletes.
With the All Blacks six months a year, he dedicates much of the rest of his time to reading sports science, brainstorming with students and collaborating on research.
He says he uses his academic work to stimulate his thinking for the All Blacks because "the complexity of rugby at top level is immense".
Despite his sharp brain, Gill believes the All Blacks are smarter, saying he would struggle to memorise their lineouts.
He believes their mental edge sets them apart, giving Richie McCaw as an example.
"He's very, very fit, but he's very slow. But, he's got an amazing head ... the physical speed is irrelevant because his thinking speed is so good."
In many ways, working with such a motivated and talented elite is a career pinnacle, and Gill hopes to stay with the side for a long time yet.
"I just wanna keep doing what I'm doing. I love it."
The last two years, Gill has also worked with Air NZ to create a leaner pilot workforce, generating health and economic benefits for the company. "Body weight is fuel cost, right." He says the job has been immensely satisfying.
"Some of these pilots have lost 20kg, gone off all their medication - cholesterol, blood pressure meds, you name it - and it has significantly changed their lives, and to a degree that is more rewarding than helping an All Black lift 10kg more."
Gill teaches them about lifestyle change, which he says has to be sustainable because deprivation "doesn't help and it lasts for five seconds".
"If it's worth doing, it has to be worth doing forever. I'll always have a beer - I'm not gonna not have a beer - I'll just understand a beer costs me 10 minutes."
He recommends limiting white food, particularly at night, and eating a rainbow of colours everyday, but admits to eating a king-size block of chocolate himself each week at home.
"I just have smart choices at every other time of the day. People either diet and are unhappy or they do too much exercise and eat what they want and are unhappy.
So being able to combine the food you love with a little bit of activity and be healthy is gold."
Gill works with the All Blacks' nutritionist to keep a close eye on what the players are consuming, and practices what he preaches. "I take myself to levels of fitness where the players are at and I'll get leaner than the players and I'll get fitter than the players."
He is also extremely flexible, surprising the photographer and I by suddenly putting his foot behind his head in a striking display of flexibility.
He encourages everyone to do the "foot and mouth stretch" and aims to get the All Blacks back to the flexibility they had as babies.
He is also passionate about sharing this message with a wider audience and has worked with primary teachers at Tauranga's Bethlehem College to include flexibility as part of the school routine.
His tips include getting kids to squat rather than sit cross-legged on the mat. "By the time they get to 20, they hopefully can still move well and be healthy and if they want to be athletes, they'll be better athletes."
Gill has called Tauranga home since the end of 2009 and he and Mel have a stake in the city's new Aspire fitness centre.
Aspire has already given scholarships to 17 Tauranga high school athletes competing at regional and national level in sports including hockey, swimming, volleyball and rugby.
NZME
