Panthers of the last few seasons have been the benchmark for fitness, so Kurt would have a yard stick. It will be interesting to see how it translates in a few weeks.
Penrith's extreme fitness compared to other teams is an illusion. A mix of Cleary long kicks, Edwards always running at the same speed and never slowing down when he's roaming accords the field and getting to the ball quicker than other FB's so there's less metres for the forwards to get behind the ball, running in numbers in attack making defences not get enough numbers in the tackle as they like and therefor the guy running the ball expands less energy fighting to win the ruck all create this illusion that Penrith are way fitter than other team. We are a fit team but it's an illusion we're at a bench mark. You could see that illusion broken in that game early in the year against the Broncos when our boys looked tired as in the last 10 compared to the the Broncos pack.
There's an episode of the Game Plan in 2020 where Matt Elliot talks about running in numbers and the illusion of an extreme degree of fitness Penrith were creating with it.
Physically whichever team Madge coaches is always the fittest. He can't coach anything less. I've seen an ex player say players at Souths when Madge was there have said to him the crazy army camps they went through were over the top it shortened some of their careers one or two years (he isn't that bad now but still pretty extreme). The problem is he's so extreme that he can over train the players unless they aren't willing to buy in and fully willing to go to an extreme level they get over tired. The Storm used to be that extreme but after they got roasted by Manly in that gf with a team 20 million over the cap they figured out they were being over trained and too tired in the business end of the season.