He was the kid from O'Connor who grew up mad for rugby but was never able to play it again after being diagnosed with a heart condition at age 14.

He's also the adult who's learnt to manage his health, completing marathons and an iron man along the way.

And in the meantime, Spencer has also created a highly successful customised sports apparel business, ONTHEGO (OTG).

It outfits everyone from Australia's national hockey teams, the Hockeyroos and the Kookaburras, to English football club, Sheffield, to grassroots kids' clubs in the bush.

The company began as a start-up in 2012 while Spencer was studying sports science and then business in what turned out to be short-lived stint at the University of Canberra. He began printing customised jerseys in his parents' garage.

"I started ONTHEGO about three months into university and got my first customer, which was the Goulburn-Mulwaree Council, on the Friday and dropped out of uni on the Monday," he said.

Spencer revealed on Friday, the International Day of Sport for Development and Peace, that his company would be donating more than $100,000 a year to charities and community groups through its new Make for Good program.

International Day of Sports for Peace and Development is about raising awareness for children to have access sport as a fundamental right. And that's something Spencer also wants to promote.

First up was a $3000 donation to PCYC Goulburn to help children in the region participate in team sports.

"We'll choose an association we find fits our values and give away anything from $2000 to $10,000 in cash or contributed goods, depending on their requirements," he said.

"And PCYC in Goulburn is pretty aligned to our values, helping people who don't have the money to buy uniforms or don't have the money to play team sports, to get into team sports.

"A lot of kids are in a position where they can't afford their team shirts for the season so the PCYC will be choosing kids from broken homes or socially disadvantaged homes and giving them their shirt free of charge."

Spencer, 27, who was born and bred in Canberra, said he wanted to give children the same opportunities he received, when sport helped him push past some significant obstacles.

"I was born with severe short-sighted eyesight. I had minus 16 eyesight, which is pretty bad. So I wear contacts to kind of counter that but sport for me was the thing that kept me pretty confident growing up," he said.

"I then had two heart conditions which put me into hospital a lot during my teens and even into my twenties as well.

"I've gone through personal adversity, personal challenges and realised sport is what helps us break from that and that's why it's so important."

At 14, he was diagnosed with atrial fibrillation, an abnormal heart rhythm, and later, supraventricular tachycardia (SVT), which can send the heart racing to 300 beats per minute.

He had to stop playing rugby -and all team sports.

"That was pretty hard," he said.

"But then I realised the love for mountain biking and cycling. That I could control my heart rate myself. Sport has always been my outlet.

"I've completed an iron man, two marathons and a few half-marathons. Our company's motto is 'every day matters' and I definitely live that.

"I've had to grow up pretty quickly and learn how far I can push myself in both business pressure and life pressure but I think the good thing it's taught me you can manage a lot.

"But well being is everything. It's no good having a great business, great car, great income if you don't have your health."

Spencer attended St Joseph's primary school in O'Connor and Daramalan College. He worked as a teenager at Sportsman's Warehouse in Fyshwick. ("That was where I found my love of products and retail and customer experience".)

His parents Cathy and Greg still live in Canberra. Spencer does too but travels to Melbourne almost weekly to meet with staff there. OTG's headquarters are in Mitchell in the ACT.

The company produces more than 200 items, from socks to polo shirts to jerseys and travel bags. It has set up an online system where customers can quickly customise and design their own gear with the click of a few buttons.

"We can turn products around in two weeks, four weeks, fully customised while other competitors will sort of take six, eight or 10 weeks. So we've got the technology advancements and speed of delivery," he said.

The business has grown fast. Two years ago, Spencer famously convinced three "sharks" on the TV show Shark Tank to invest $600,000 in OTG. The deal never passed due diligence. But OTG didn't need the leg-up in any case.

"It's kind of controlled chaos," Spencer said, of running the business.

"We've grown from a company of 12 staff a year ago to now 30 and we'll probably by over 50 by December. They company's revenues have grown two to three times in size every year.

"It's a very fun place to work."

While the company supplies grassroots sporting teams, it also has deals to supply the Kookaburra and Hockeyroos until 2025 and the Sheffield football club in England.

"As a result of that, we're in discussions with some European football clubs and British football clubs and that's been quite a success for us," he said.

"It's also laid the groundwork for us to expand into the UK later this year with our internet business."

And more developments are on the way.

"We've got some big announcements coming up. One of biggest companies in our Australia will be white labelling our software for their businesses so they can have similar products for their customers," he said.

Spencer will also marry his fiancee, Canberra physiotherapist Alicia Jackson, at Whale Beach next March. He's happy to also be on the go.

"It's a busy life," he said.

Spencer has treated himself to property and a nice car - a 2012 Aston Martin Vantage - but has invested most of the profit back into the business. He remains the major shareholder.

The company conducts all its R and D in Australia and the rush orders that need to be done in five to 10 days are also made in Australia. Bulk orders are manufactured in China, the Philippines and Pakistan. He says the company only uses ethical outlets and will not abide any association with sweat shops.

"OTG strives for excellence in manufacturing. Throughout Australia and South-East Asia, as well as our makers in Pakistan, we run to a strict global ethical sourcing policy we have created in conjunction with experts in the field of manufacturing," he said.

Ultimately, Spencer wants the same success for the kid down the road as he has had.

"We had 60 Year Six kids come in for a tour of the premises in Canberra which was great and I was saying to them whether it's sport or business, you've got to find your outlet to keep you confident and you've got to invest some time into it," he said.

"Often society puts a lot of pressure on us and in sport you learn the fundamentals of life which are communicating with a team, not letting anyone down and routine - turning up to do your job, whether you feel good or bad. I think it's important for youngsters to see sport as a development path."