Conor McGregor may have the one-punch knockout power, but in the other end of the spectrum, his cardio has been suspect at times. Two notable losses of his career have been because of gassing out: UFC 196 in 2016 against Nate Diaz, and against Floyd Mayweather Jr. last August.

People point to poor conditioning, but for Tristar Gym head coach Firas Zahabi, there is a deeper root to the problem.

“It think it’s partly genetic,” Zahabi told Joe Rogan during the recent episode of the JRE MMA Show. “I call it the touch of death. He’s got that left hand, it’s the touch of death. That touch of death comes at a cost.”

“How do you have the touch of death? Where does power come from? Number one on the list, number one, is where your muscle is attached to the bone. It’s genetic. So, Mike Tyson, he has a powerful left hook not because his coach taught him how to hit a left hook. He could have hit a left hook like that if he had a mediocre trainer.”

“It has to do with the leverage of his bones,” he continued. “So, for instance, imagine a really heavy pole that weighs a hundred pounds, and I want to stand it up. Well, depending on where I grab it, I’m gonna have more resistance or less resistance. If I grab it near the end, I have more leverage. So where your muscles are attached to the bone is gonna dictate how much leverage you get out of it.”

Zahabi went on to further explain how the type of muscle fiber in one’s body can also be a great contributing factor.

“If you have a fast-twitch muscle fiber, you can hold less oxygen, but it can twitch faster. Hence the name,” Zahabi explained. “So, if you’re a slow-twitch muscle fiber guy, you can metabolize more oxygen, but you can’t twitch as fast. So, there’s a give and take.”

“So you have a guy like Nick Diaz who needs to knock you out with volume. He can’t knock you out with one shot,” he added. “Look at B.J. Penn. If round one, he doesn’t knock you out, the likelihood of him knocking you out in round two is less. Diaz is the opposite. The likelihood of him knocking you out in round three is higher than round one, because of the cumulative attack.”

“McGregor, look at his stats. It’s all round one knockout, round two knockout (using) his fast-twitch, high-leverage left hand. If you take him into deep waters, his fast-twitch muscle fibers cannot metabolize with Mayweather. Mayweather’s so smart, he let McGregor work for three rounds.”

“’I knew you’re getting excited, keep working. And when you have nothing left, I’m gonna put you out.’ That was such a brilliant strategy.”

While McGregor’s next fight date and opponent is still far from being determined, one of the biggest talks as of late is a possible matchup against current lightweight champion Khabib Nurmagomedov. “The Eagle” is known for his relentless wrestling and grappling, but SBG Dublin striking coach Owen Roddy is confident that McGregor would be able to handle that kind of pace.