By Michael Whiting

Aerobic endurance improvement has been a theme for Gold Coast SUNS players this pre-season and it hasn't been only the younger players making a mark.

In just their second pre-season at AFL level, it was expected the majority of the club's 18- to 20-year-olds would rapidly improve their performance over the club's endurance test - a 2km time trial.

And while the first- and second-year players have done that, it's a few of the more experienced players that have caught the eye.

Arguably the GC SUNS fittest player, defender Joel Wilkinson notched another personal best over the distance after returning from a two-week Christmas break, but he was not the only player to slash their time.

"The whole group improved, it wasn't just myself, a lot of the boys came back with personal bests," Wilkinson said.

"The older guys definitely improved, Nathan Bock, Michael Rischitelli and Karmichael Hunt are three off the top of my head that definitely improved."

Wilkinson said the two-week altitude camp in Arizona during November had a positive effect, but the fact a majority of players kept improving after Christmas showed they did not slacken off over their break.

"I guess we realised after playing last year how tough the AFL is, it's a full-time job, and we understand that even though it's a break we have to work hard to get the rewards," he said.

"I think it's about continuously pushing your body every session. I think once you hit a high level of fitness you have to find that one and two per cent.

"It's now about translating that into [becoming] a hard-running football side."

Fellow second-year player Luke Russell has been another big improver, dropping his 2km time by 13 seconds.

The small forward said he was hopeful his improved fitness would earn him a rotation in the midfield when the season started in March.

"The NAB Cup is coming up soon and I want to get myself right for that and be consistent through there and be an option for round one," he said.