It is no secret Jack Grealish enjoyed himself on his month-long booze-filled holiday after Manchester City won a sensational Treble in the 2022-23 campaign. 

But once he was done, he headed out to Dubai to get back to work before joining up with his team-mates for pre-season. There was only one man he called to help him out: Nike trainer Jamie Reynolds – the secret to the success of sport’s biggest names.

Topless and bathed in sweat, Grealish shared a video on Instagram and panned the camera around to focus on Reynolds on a sun-beaten AstroTurf pitch.

He is a guru in the art of calisthenics, a form of exercise which uses body weight for resistance rather than external weights of equipment. As a result, Reynolds has proven himself adept at building up the size of athletes, as well as their strength.

Simply, he leaves no stone unturned, and that’s why sporting icons have turned to him in their droves to get the crucial edge over their competitors. It is also no coincidence that many of them frequently return to work with him again and again.

Nike trainer Jamie Reynolds works with a number of high-profile stars (above: Jack Grealish)

Reynolds has regularly linked up with Grealish to help him work on his fitness

He is a favourite of Marcus Rashford and put him through his paces before he joined Barcelona

Grealish is one such example. The playmaker, outcasted by Pep Guardiola and given permission to train individually as he waits on a move away from City, has linked back up with Reynolds this summer. Highlights of their sessions were posted online.

Rashford, Phil Foden and Bruno Fernandes are just a few of the many athletes who have also joined up with Reynolds, who is known as Jamie ‘Velocity’ on social media. 

His track record speaks volumes. Just ask Jose Mourinho, who revealed he was left open-mouthed with Rashford’s physical evolution during pre-season in 2017. Rashford leaned on him again as he geared up for his dream switch to Barcelona.

One quick glance at Reynolds’ Instagram page tells you everything.

The top three pinned posts are shots of him working with Grealish, Ronaldo and Joshua. Earlier this week, Reynolds shared a training montage featuring Rashford, which he pertinently captioned, ‘Hard work beats talent.’

Two days before that, he uploaded a series of photos of a session with Grealish and waxed lyrical about the forward, saying ‘What a player, what a guy.’

His reputation precedes him and Reynolds has quickly become the go-to guy for athletes up and down the country. Clearly, his methods have a remarkable effect.

There are countless other case studies underlining just that.

Reynolds shared a photo of himself posing with Cristiano Ronaldo on his Instagram page

He has been hailed as the secret weapon behind Anthony Joshua’s brutal knockout power

In July 2020, shortly after most Covid restrictions were lifted, Chelsea shared videos of home workouts featuring Mason Mount and Reynolds, posting them on YouTube. 

Troy Deeney, who played for Watford in the top-flight, saw a friend train with Reynolds and recalled being struck by the power of his cutting-edge approach. He went on to work religiously with the trainer for boot camps before pre-season.

These sessions focused particularly on his footwork and agility, while he also used Reynolds in sessions built around the Premier League’s brutal, packed calendar. 

Deeney spoke glowingly of Reynolds, telling FourFourTwo: ‘He’s the first trainer who told me what physical attributes I needed as a striker, my strengths and weaknesses, and then said, “I want you to keep working at your strengths.”

‘I’d never worked with anyone specifically on my game before – previously I’d just done a training programme that had been developed for a whole squad of players.’ 

Crucially, Reynolds says his techniques are perfectly suited to a variety of sports.

He told Men’s Fitness: ‘When it comes to the work that these guys do in the gym, the truth is that around 70 to 80 per cent of it is the same no matter the sport.

‘The principles used to help make a footballer stronger aren’t going to vary too much to those used to add strength to an NFL player, or a tennis player, or a boxer.

Reynolds joined Grealish in Dubai shortly after Manchester City won the Treble

Bruno Fernandes shared some helpful shooting tips with Reynolds in a social media video

‘The differences come when we look at how to transfer what we learn in the gym to the pitch/ring/court and also how we train the athletes’ energy systems for the specific demands of their sport/position.’

More so now than ever before, athletes are willing to do anything to extract an extra one per cent of performance – potentially the difference between glory or defeat.

Trainers like Reynolds, therefore, will become increasingly important and he will without a doubt continue to be the No 1 trusted coach athletes turn to first.

The only trouble is: They’d better get in line.