Constantine competed overseas from 1981, when he won the 20km at the World Games, until 1987. During his 14 years in the sport Constantine won a total of 48 New Zealand titles and for five seasons he raced at the Bononia Fini Sport club in Italy.
Like many athletes in minority sports or those who are building up to international glory Constantine had to work to pay his way - although his clubs helped fundraise and he had some funding from the former New Zealand Sports Foundation.
Constantine's first career was as a tradesman and his absences for competing and travelling abroad did cause discord with management and colleagues. In his second role Constantine reported to "the first adult in my life who could see the crossover between the attributes that make a top sports person and a good employee".
Even so, without the career and psychological help that some athletes get now, there was "blood and guts" in his post sport career.
"Sport defined who I was," says Constantine. "When I finished my sport and in particular when I left the competitive environment, I completely lost my identity. But what's more, almost all the guiding structures and norms around me disappeared as well."
Constantine transitioned into management roles soon after retiring from speed skating, a move that he was not prepared for.
"I was catapulted into management because I was driven. I had a whole bunch of attributes, but no road map. It was haphazard, so there were some calamities as well as successes. With the right guidance it would have been smoother and more effective," he says.
Constantine has worked in the organisational development field for the past 20 years. He says there is seldom a week that goes by where he is not leveraging from a core set of personal skills that were developed during his time as a top-class athlete.
Sports people such as Constantine often do have many transferable skills - although they may not realise it, says Glenys Ker, facilitator at Capable New Zealand and lecturer at Otago Polytechnic.
Ker currently works with elite athletes to assess their prior learning skills which can be credited towards degrees such as the bachelor of applied management at Otago Polytechnic. Many, but not all major in sports management. They often transition well into marketing careers as well as business, says Ker.
Some athletes have a clear idea of what they will do in life after sport and can reflect, says Ker. Others simply don't think about it. If they are prepared to engage, they are usually taken through a set of tools to help them identify their attributes and understand who they are. That may be a card sort exercise, a narrative, or a computer-based programme.
With some athletes Ker's approach can be to ask confrontational questions. To ensure that they have a plan B, C, and D, for when their sporting career ends.
These days "carded" athletes that make it to the top of their sport internationally get considerable career and life help from High Performance Sport New Zealand. Former international rower Nathan Twaddle was a beneficiary of that assistance and has worked since 2010 as an athlete life adviser for High Performance Sport.
The programme for carded athletes acknowledges the price athletes pay by missing the earlier stages of an employment career, says Twaddle.
The assistance comes in three parts. When athletes first join the programme they are usually six to eight years out from pinnacle events such as the Olympics. They are given a general introduction as to how the system works and are taught soft skills.
As the athletes progress they are given access to sponsorship money for education and advice on how to best use that money and organise their schedules to fit study in.
The third stage, at the pinnacle of their sporting careers, athletes are counselled about moving into their work career.
"It is about getting them to understand what that transition is going to be like so they are aware of the hurdles," says Twaddle.
The athletes are helped to build connections in the industries they may be interested in entering.
"Sometimes they have a slightly romantic idea about what a career might be," says Twaddle. "We get them to meet senior business people to give them an idea of where they could go."
There are also practical skills such as interview preparation, CV writing and career exploration.
One group that misses out on all this is the athletes who commit their lives to competing, but don't make the grade.
They may find themselves at the end of their sporting careers at an early age thanks to injury or deselection and many go through a process akin to grief, says Ker. Some will seek advice independently. But others find themselves going through a long painful process that may take five to 10 years to get through.
Some sports such as Netball New Zealand are better than others, says Ker, at supporting these players who didn't make the grade.