Many a great sportsman, once they have lost half a yard in pace or feel the chill of approaching middle age, swap the training ground for the boardroom.
Retired World Championship hurdling silver medallist Jon Ridgeon is now a director of sports marketing agency Fast Track, for example, while Sebastian Coe's career has jumped from middle-distance runner to MP to peer and chairman of LOCOG.
James O'Shea, marketing director for Maxinutrition, the company behind sports-nutrition brand Maximuscle, was also something of a sporting wunderkind: his ranking as a top 20 national squash player and a top hockey player in his teens meant he could have tried to make a career as a sportsman.
Of his choice not to, he admits he has regrets. 'I stopped playing squash in my gap year, so I fell a year behind everyone else and there was not a huge amount of money in the sport as there is today.'
While he did not reach the sporting heights of Coe and Ridgeon, he is on track to make a name for himself as an eminent sports marketer.
O'Shea still has an athletic physique, but a couple of kids and a move up the corporate ladder have forced him to swap squash for the more sedate game of golf - and even that is starting to fall by the wayside.
When he joined Maxinutrition, O'Shea was continuing a sporting theme that has dominated his career to date. Having gained a 'fantastic overview of marketing' working on accounts such as NBA and Carlsberg at agency Prospective Marketing, O'Shea jumped ship to Nestle and General Mills' joint venture Cereal Partners, where he worked on brands such as Shredded Wheat.
This afforded him the chance to meet brand frontman, former England cricketer Ian Botham ('a pretty straight-down-the-line bloke'), as well as play a leading role in Cereal Partners' 'Good for your heart' campaign, which involved complex negotiations with TV regulator Clearcast.
After three years, he moved into the world of brewing, joining Carlsberg as brand manager for Tetley's Bitter, helping launch a TV campaign and exploiting its England rugby sponsorship.
O'Shea describes his time at Carlsberg as putting him right at the coal face. 'I took the product to the pubs as well as the supermarkets,' he says. 'However, it was difficult to "own" projects, which became frustrating and was a key reason why I left.'
While owning projects has been part of O'Shea's remit to date at Maxinutrition, the game changed last December when pharmaceuticals and consumer healthcare products company GlaxoSmithKline bought the firm for £162m.
In Maximuscle, GSK is getting a proven product, a useful asset in a sector it has hitherto failed to crack after trying to launch protein drinks under its Lucozade brand.
The backing of GSK has given a fillip to a sports-nutrition industry that, to an extent, remains misunderstood and mistrusted. Some still believe protein supplements are no more efficacious or health-enhancing than a balanced diet and a good night's sleep. Others still harbour misgivings because the industry has been hit by rogue operators looking to earn a quick buck.
However, none of these accusations has been levelled at Maxinutrition, which has railed against the rogues and sought to bring credibility to the sports-nutrition industry. The brand can now be found even on Tesco's store shelves.
'Argos came first,' says O'Shea. 'It took us a while to get Tesco on board. Now it is stocked in Morrisons and Boots, and this has helped normalise the product.'
The support of brand ambassadors such as cricketer Stuart Broad and footballer Jermaine Jenas have also helped enhance its appeal. Now, O'Shea and his 15-strong team want to take it beyond elite sportsmen and gym rats to the mainstream.
'The questions about the benefits of protein are still in the market place, and our marketing is about addressing these concerns,' he says. To this end, Maxinutrition's marketing now features its star players alongside amateur sports enthusiasts.
The selling point for the portfolio, which includes Maximuscle as well as the Maxifuel and Maxitone brands, is that they help repair and rebuild muscles following exercise. Conveying the science behind the brands in their marketing is a challenge.
'It comes back to education, which is at the heart of our marketing,' says O'Shea. 'It is about explaining the power of protein. It is not going to happen overnight, but our role is to continue to educate.'
A boost to its ad budget is intended to help solve this issue, while raising awareness of the brand with the wider public.
Along with increased ad investment, overseas expansion and improved distribution are now on the cards. The additional possibility of cross-promotion is an interesting one, with Lucozade an intriguing fit.
Another key growth area is ready-to-drink. 'GSK has about 80,000 chillers and vending machines,' he explains. 'RTD is currently only a small part of our business, so this could prove massive for us. GSK is also first-class at research supporting its products; that could be another advantage.'
According to O'Shea, the relationship with GSK is arm's length and, hitherto, rosy. 'Maximucle is staying as an independent business,' he says. 'This is part of the beauty of the deal.' Executives from GSK and Maxinutrition meet once a week to discuss how to maximise what the parent company now calls the 'Maximagic'.
Having first taken the brand on to TV last year, O'Shea is gearing up for a major TV ad burst next month, as he looks to raise awareness ahead of London 2012. O'Shea describes this period as a potential 'game-changer' for the brand.
He brims with enthusiasm for London 2012, with good reason. Having initially rejected a deal with Maxinutrition, UK Sport, the government-backed body that oversees the country's development of high-performance sport, performed a U-turn and signed a deal for Maxinutrition to develop products that British athletes will use in the run-up to the Olympics.
O'Shea is lively and talkative, and one gets the impression he likes the limelight - an opportunity his previous roles did not afford him. With hindsight, he says his biggest regret was that he did not trust his instincts and leave Carlsberg earlier. But that said, he is still only 35, and happy, for the foreseeable future, at Maximuscle.
Even so, he does harbour ambitions to take his sport-themed career to a new level.
'My dream job would be to work at Nike, but this is pretty close to it. I'm living the brand inside and outside work.'
2000-2003: Assistant brand manager, rising to brand manager of Shredded Wheat, Cereal Partners
2003-2005: Brand manager for Tetley's Bitter, Carlsberg
2005-present: Marketing controller, rising to marketing director, Maxinutrition
Favourite sportsman: Michael Jordan
Favourite ad: Honda's 'Cog'
Most-admired person in business: Philip Knight (Nike co-founder and chairman).