The specter of Mexico City’s altitude looms large for many fighters as UFC Fight Night 98 draws near. Beneil Dariush is among those preparing for the altitude and pollution, and the impact it may have on his cardio.

Dariush (13-2 MMA, 7-2 UFC) faces lightweight Rashid Magomedov (19-1 MMA, 4-0 UFC) at the event, which takes place Saturday at Mexico City Arena. The card, including the Dariush vs. Magomedov main-card bout, airs on FS1 following early prelims on UFC Fight Pass.

A loss to Michael Chiesa at UFC on FOX 19 in April snapped a five-fight winning streak for Dariush – one that had placed him in the conversation as a potential future title challenger.

A brilliant first-round knockout win over James Vick at UFC 199 reestablished Dariush as a force in the division, and he now sits No. 10 in the USA TODAY Sports/MMAjunkie MMA lightweight rankings.

To keep moving forward, Dariush needs to be the first man to defeat Magomedov in the UFC octagon. He and his team are taking the task seriously, first training in high altitude at Mammoth Lake, Calif., before heading early to Mexico City.

“The first time we went to Mammoth, we were walking up the stairs with our luggage, and I felt it,” Dariush told MMAjunkie Radio. “I was breathing heavy and couldn’t breathe.

“Mammoth has a couple things. It’s higher cleaner air, and it’s easier for us to train there. We have a good location. That’s why we picked Mammoth. Originally, we wanted to come here earlier, but when we came to Mammoth, we decided it was the best place to train at.”

Former heavyweight champ Fabricio Werdum is no stranger to the complications that come with fighting in Mexico City. He captured the title at UFC 188, surprising many with a deeper gas tank than cardio-crazy Cain Velasquez before scoring a third-round submission.

Werdum gave some advice to Dariush as he prepared for the fight.

“He mentioned altitude, but he also mentioned food,” Dariush said.

“Fabricio usually doesn’t eat that well, but even Fabricio said, ‘Hey, be careful of what you eat over there so you don’t get sick.’ For him, I think he even told me one of the biggest things for coming out here early was that it allowed him to focus more.”

If anything, Dariush said the focus on training may have gone too far. He said he found himself at risk of overtraining at times. Toward the end of his time in Mammoth Lake, Dariush had a particularly difficult sparring session and had to cut things short.

“My last Friday sparring, instead of doing the full six rounds, I only did three,” Dariush said. “I was just getting beat up, and I wasn’t able to – I may have been overtrained. I was trying to return punches, but I was just getting whooped. Even my trainer said, ‘Hey, man, go sit out. We don’t need you getting a concussion.’ What helped me turn that around was – I’m a simple guy. I went home and prayed, and that usually helps lift my spirit.”

For more on UFC Fight Night 98, check out the UFC Rumors section of the site.

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