Back in Australia, elite sportsmen would barely raise a sweat walking at a steady pace - at 8,000 feet it's a whole other story.
With coach Brad Scott leading the players out for their second hike, the travelling group was on the move for almost three hours, a steep climb making the task even tougher.
"At altitude you have a lower partial pressure of oxygen. It just basically means that the muscles that are working are having to work harder to get the oxygen they need, and the energy they need," Nutrition and Conditioning Coach Jona Segal told NMFC.com.au.
"You feel your heart-rate jump up, you feel your respiratory rate jump up, and a hill that's certainly manageable at sea level becomes a different proposition all together."
PRESS PLAY above to watch vision and interviews from the hike | YouTube
Trent Dumont and Brad McKenzie were among those at the front of the pack, as the players continued to acclimatise to the tough conditions.
"The guys are unbelievable athletes. They only know one way and if the session is get to point x, they get to point x," Segal added.
"The spirit is great. As they are going you can hear them (the players) puffing and panting, but they'll still play some games and keep themselves amused, while getting a really good session under their belt as well."
Another notable inclusion on day five, Chief Executive Officer Carl Dilena joined the players for training.
"It's good for the younger players this year to try to build that base (of fitness). Over the last few years it's been really good for the development of our players, so hopefully this year does the same," Dilena said.
By 11.30am, the players were back at the team hotel. It didn't end there though. After a quick swim, then lunch, it was back to Newpark for skills.
Stay tuned for video from the hike, available soon on NMFC.com.au.