Phil Coles lauded Liverpool's "unbelievable" physicality as Jurgen Klopp's high-octane European champions dominate English football.

Klopp's 'heavy metal' football has transformed Anfield, the charismatic German helping to restore the glory days after last season's Champions League triumph.

Liverpool were also on track to win their first league title since 1990 prior to the coronavirus pandemic – the Reds were 25 points clear atop the Premier League table through 29 matches.

Klopp has overhauled Liverpool's style of football since replacing Brendan Rodgers in 2015 – his Gegenpressing philosophy restoring the club's position among the world's elite clubs.

Coles is no stranger to Liverpool's inner sanctum, having previously worked as the team's head of physical therapy under former bosses Rodgers, Kenny Dalglish and Roy Hodgson between 2010 and 2012.

So what does the Australian – who now works as executive director of performance at NBA franchise the Boston Celtics – think about Klopp's high-flying Reds?

"Looking from the outside, and I don't have any special data or information on anything they've done, but they do look incredibly good physically," Coles told Stats Perform News.

"The style Klopp plays with the press and counter-attack – it expends a lot of energy. The way the full-backs play is incredible, with the engines they have. Both full-backs getting up and down.

"So, they are clearly a physically gifted side and you would have to credit the approach of the club as a whole to giving that to them.

"Partly that can be in the recruitment of players who will fit in the style that Klopp wants. Partly it's gonna have to do with the coaching and the way he structures his sessions that are going to allow them to achieve what they need.

"And partly it's no doubt due to the performance staff there, who are clearly doing a fantastic job to get those guys at the level they're playing. Not only are they playing unbelievably good football and I think personally, if the season was to stop now, they should be crowned champions because they are clearly the dominant side and certainly deserve it.

"It's not just how good they are playing but the physicality of how they play is unbelievable. The performance staff have clearly done a fantastic job but I think it's a club-wide approach, to achieve the success they've had, everyone has to be contributing – from the players they recruit, to how the coach sets up and runs practice sessions, to how the performance staff contribute.

"All of those things have to be in sync to be at the level that they're at, both physically and functionally for how well they're playing."

Former Borussia Dortmund goalkeeper and current Australia international Mitch Langerak recently provided an insight into Klopp's relentless methods during his time at Signal Iduna Park.

Langerak told Stats Perform News: "He's full power… For example, when I first arrived [in 2010], I didn't know what a training camp was because I hadn't been on one with Melbourne Victory. We turned up and my agents were saying 'oh wait for the training camp, wait for the training camp'. I'm like what's with the training camp? I thought we'd just go and do a bit of training. We were doing three sessions a day, then the next day we'd have a double, then the next day we'd have training in the morning, a 'friendly' game at 4pm that afternoon but a friendly game with Dortmund is in front of 30,000 people.

"The next day you'd have a double, a triple. So you're up at 7 in the morning. You'd do lactate testing, so they would know if you're in the fast group of five players or next group. You'd do 5km or 6km in 1km time-trials and you just have to keep your pace. The boys would be blowing, they'd be wrecked. That was at 7am in the morning before breakfast. You'd go back to the hotel, have a quick bite to eat, you'd get showered and changed and then you'd go training. You'd do a proper, proper training session. Go back, have lunch, maybe sleep for an hour and you're back at 4pm for the third session of the day. This is day one of training camp, Day two could be a double, day three is training and then at 4pm a friendly game in a stadium live on TV in front of 30-40,000 people.

"It's actually so nuts but it wasn't like 'oh he needs to have a rest today, he's 32, he's coming back from injury so he needs to have a light one today'. It was none of that, if you train, you train. That was the biggest thing for me. It was just like, obviously after seven days of training you're a bit sore, bit tight maybe we should have an easy session. Nah, you learn to just get on with things and grind it out.

"Some of the training sessions were intense but then when he could see the players getting tired, he was like 'that's it we're finished for today, come back tomorrow and we'll smash it again'. I think that with a lot of young, hungry players it worked really well. He was obviously the alpha, the boss. You can see that within the whole club – he was the one in charge and everyone had so much respect for him."