Much has been made of the way that Shane Carwin appeared to run out of gas after the first round of his UFC 116 title fight against Brock Lesnar.
Some people have been very critical of Carwin, saying he lacks cardio conditioning. Carwin denied that the issue was with his cardio, but instead was due to cramping.
Whether it was cramps or cardio is irrelevant.
It's clear that Carwin was far depleted by the end of the first round. Despite that, I think the fuss over Carwin's cardio is a bit ridiculous, and that criticisms over his fitness levels have been vastly overstated.
Carwin pounced on Lesnar early in the first round and bombarded him with power shots in an attempt to finish the fight. That he would run into issues of cramping or cardio is simply a matter of physics.
Weighing in at over 265 pounds by the time he steps into the cage, Carwin is a massive heavyweight. Yet despite how big his muscles are, the most important muscle, the heart, has limitations on how big and how powerful it can become.
Any 265 pound man exerting himself fully for five minutes, as Carwin did, would become tired.
Furthering the problem is Carwin's physical power. Here is a quick equation to demonstrate why Carwin's gassing should have been completely unsurprising.
A: We know Carwin is an extremely hard puncher.
B: Fightmetric tells us Carwin attempted 106 strikes against Lesnar, including 77 power shots.
C: Harder punches cost more energy than weaker punches.
D: 106 strikes in five minutes is a lot. Compare that to the 108 strikes Lesnar attempted on Heath Herring over the course of a three-round stomping.
The conclusion we should be able to draw from these facts is the energy Carwin used up over the course of the first round must have been enormous.
He punched himself out, plain and simple.
Going forward, I don't see this as necessarily a bad thing for Shane Carwin.
Carwin had never faced someone who could stand up to the kind of punishment he could deliver, and the truth is there are few other people in the world who could.
It should be quite obvious at this point that Lesnar is an extremely durable fighter. Most other fighters would not have lasted past the second minute of the onslaught.
Yet even if there are other fighters out there who can deal with Carwin's power, that still wouldn't necessarily be a problem for Carwin.
If Carwin paces himself in future bouts, I see no reason why he wouldn't be able to still have success over three, or even five, rounds.
Yes, Carwin was spent after five minutes.
What people forget is conditioning isn't just about endurance over a period of time. The amount of energy expended over that time is the key issue that seems to be greatly overlooked.