Hayes (28) resigned from her job as manager of the Moana Pool gymnasium at the end of last year to become a professional triathlete.
She has given herself two years to see if she can make a success of her new career.
Her most important lesson came in Amsterdam when she was in third spot and would have collected prize money of $NZ7000 had she finished.
''There are so many things that can go wrong in the Iron Man over the 3.8km swim, 180km bike and 42km run,'' Hayes said. ''It is a mental game.''
It was a cold and wet day.
''When you are on a bike for five hours in the pouring rain, you're freezing,'' she said. She pulled out after 12km of the marathon.
''I thought I would feel better if I stopped running,'' Hayes said.
''At that moment I felt that my legs could not hold me up. The next day my legs were fine, so it was all in my head.''
Hayes learnt the hard lesson of how to get herself out of the mental state she was in.
She had been a successful rower in her teens and won four Maadi Cup titles and two open New Zealand titles when she trained with coach Sergio Salis.
However, it is not all glamour being a professional triathlete..
''It's pretty good to do what you love doing every day,'' she said.
''But it is not just a life of training and relaxing.
''It is stressful turning up to races when it is your job and you have to perform well to make a living. You are not just doing it for fun any more.''
Hayes has returned home to Dunedin after three months' racing in Europe and has made a self-assessment after 10 months as a professional athlete.
''I've learnt what to do and what not to do,'' she said.
''Next year, my plan of attack for racing and training will be different.''
Hayes intends to race less and train more. This year, she had six races in New Zealand before going to Germany for three months and having six major races. She still has five races at home before the end of the year.
''I will pick my races better than I did this year,'' she said. Hayes found it difficult earning a living but made ends meet through sponsorship and prize money.
''In Germany I was lucky to have a host family who provided food and accommodation for three months,'' she said.
''The prize money from races paid for my trip.
''I covered my expenses but you don't do the sport to get rich.''
Her major sponsor, Dunedin firm Active Electro, made it possible for Hayes to experience the European circuit for three months.
Hayes gained $NZ2000 for winning two Olympic-distance races at Rothsee and Erlanger, and $NZ4000 for finishing fifth at the Copenhagen Iron Man in a personal-best time of 9hr 29min.
The winner of the Iron Man at Amsterdam got $NZ15,000 in prize money.
''It seems a lot of money but when a racing bike costs $15,000, it is not much compared to what people can earn in other sports, '' she said.
Tamsyn Hayes
At a glance
Age: 28
Education: Queen's HS, University of Otago School of Physical Education.
Occupation: Personal trainer, professional triathlete.
Sports: Rowing, triathlon.
Coaches: Sergio Salis (rowing), Keegan Williams (Iron Man).
Record
Rowing: Four Maadi Cup wins, two NZ championship gold medals. Represented NZ Universities in transtasman series.
Triathlons in Europe 2013: First in Olympic distance at Rothsee and at Erlanger; 5th in Challenge Denmark half-Iron Man and 2nd at Erlanger; 5th in Copenhagen Iron Man (personal best 9hr 29min).
