Marcos Maidana is preparing to go the distance in his upcoming rematch against Floyd Mayweather Jr. on Sept. 13 at the MGM Grand Garden Arena in Las Vegas.

In an interview with BoxingScene, Raul Robles, Maidana's strength and conditioning coach, revealed that they have been performing special exercises over the past two weeks to improve the Argentine's stamina, including using an oxygen mask to regulate breathing.

"We have already had two weeks of working like this. We're doing absolutely everything we need to achieve peak excellence for this bout. We were working with medicine balls, rubber bands and the mask that dispenses oxygen. We are teaching him how to evenly manage his breathing," Robles said.

Robles said that they are looking to solve Maidana's breathing issues, saying that it was the reason why the former WBA welterweight champion failed to sustain his energy in their first showdown on May 3 in Las Vegas.

Maidana was able to put a lot of pressure on Mayweather's shoulder in the first six rounds of their first fight, but Robles admitted that the energy level was not the same from the seventh round of the fight.

"The issue of breathing is a crucial core aim of team Maidana, because in the second part of his first fight against Mayweather, his physical condition somewhat slowed down and he's determined to correct this," Robles said. "I watched the first six rounds of Maidana and he was very strong. But from round seven his performance began lowering."

As a result, Mayweather managed to control the fight from that point, and the reigning pound-for-pound king remained unbeaten in 46 fights via a majority decision victory. Robles vowed that Maidana won't commit the same mistake in the rematch.

"He didn't have such power as he'd shown up to that point. So we are now working to possess and maintain twelve rounds of intense activity," Robles said.

The Buenos Aires native Maidana, who holds a 35-4 record with 31 knockouts, also recently vowed that he will be well prepared, saying that he won't let the chance to score a big win to slip away from his hands again.

"I'm well prepared, I'll do my job and I know I can win. I'm waiting patiently for the date to come. We are sure that everything will be fine," Maidana said. "I know I have an absolutely great chance for victory. It will be very difficult just like the first fight, but I'll be well prepared to win when I get to the fight."

For the latest sports news, follow Latin Post Sports on Twitter.   

FOR MORE BOXING NEWS UPDATES, CLICK ON THIS LINK TO VISIT LATIN POST.COM'S SPORTS PAGE.