"You can do as much running as you like but you have actually got to be playing games, there is no substitute.
"And that is why Fiji excel at the game of sevens because of the simple reason they play week in and week out."
The All Blacks Sevens' season starts in December when the 2015/16 HSBC World Rugby Sevens Series gets under way. The world series finishes in May, with the Rio Olympics three months later.
The Australian Sevens team are still looking to qualify for the Olympics.
Tietjens said the past few days had provided some of their newer players a great chance to show their ability.
"It's been massive in terms of it is international competition, you know, and you can measure players and see where they sit," he said.
"And that is really good for some of these players that are looking to secure contracts, and that's good for New Zealand really because there are some good young guys who are putting their hands up, which is awesome."
Rotorua schoolboy Isaac Te Aute was among those new young players. Te Aute received plenty of game time over the weekend, not looking out of place. "Isaac is very mature for such a young footballer. He has gone very well," Tietjens said.
The three-day series was based around the next year's Olympic schedule.