Having worked as an assistant to Brett Ratten at Carlton for the previous five seasons, Riley said the Melbourne footy community had a cynical attitude towards the SUNS.
"The perception from down south, being a new fledgling club and the squad being young and the Gold Coast having a reputation of being a bit of a holiday town, I wasn't quite sure how hard the guys worked," he said on Thursday.
But what Riley has found is anything but a holiday.
"Their training ethic has been really, really good. We've trained really hard as a collective and increased the workloads quite dramatically from previous seasons according to the records and that should hold us in good stead," he said.
"When I was at the Blues, we played the SUNS in their first ever game at the Gabba (round two, 2011) and some of the changes in body shape in some of these athletes since that period is quite astronomical."
Riley's surprise at the SUNS' work ethic echoes the words of former Adelaide physical performance manager Stephen Schwerdt, who has also joined the Gold Coast in 2013.
Schwerdt recently told AFL.com.au the club's work ethic was and attitude was equal to, if not better than, the Crows, who are widely regarded as one of the most physical and athletic teams in the competition.
Riley said he enjoyed working with young players in teams on the rise and has been given the perfect role as the coach of an inexperienced forward line that includes Sam Day, Tom Lynch, Steven May and Charlie Dixon.
He said with the squeeze for positions on, it was likely some of the forwards would be tried in the backline.
"We are quite small in defence. Matty Warnock has done a very very good job, but Matty is a medium-to-tall sized defender, so was Thomas Murphy that came from Hawthorn," he said.
"We need some size down there and we're not going to be able to fit all our size in the front half.
"So some of those boys will have to develop the flexibility of playing both-ends football, and May is one of them, Day may be one and Tom Lynch may be another.
"At least we have the tools on our list, and it'll be up to us to coach them in those areas so we do have a big fella that can play on those monsters.
"There might be some pearl training in the forward line that might become a centre half-back or fullback. You've got to have guys to play on the (Travis) Clokes, the (Josh) Kennedys, the monsters of the competition.
"It's exciting, it's new, I like the idea that we're building something and I enjoy being part of that."
