Gleison Tibau is a massive UFC lightweight who weighs 181 pounds on fight night. How does he put on 26 pounds in the space of 24 hours? The guys responsible for his physical conditioning, trainers Stefane Dias and Everton Bittar, have their methods.

"Stefane Dias started this whole procedure with Gleison about five years ago," Bittar told MMA Fighting. "I developed a job at American Top Team in conjunction with Stefane Dias, we have the same line of work. There is a principle in sports training called 'biological individuality,' in which we must respect and create the camps individually.

"In Tibau’s case, Stefane started and worked for several years creating strategies for him to lose the necessary weight -- and have an adequate intake for his fights -- and I've been following through on this work without making radical changes. The athlete is used to all this work so our goal is to increasingly seek the best in each physical ability. Every fight we work is an analysis, and after his fight with Jamie Varner, we sat down to see what we could improve."

Tibau fought Varner at UFC 164 in the 155-pound division on Aug. 31. On Monday, four days before the weigh-ins, the Brazilian still needed to lose more than 20 pounds. Everything is programmed, and they never feared he wouldn't be able to lose that much in four days.

With the help of American Top Team’s nutritionist Leopoldo Leao, Tibau hit the scale at 155 on the nose at the weigh-ins on Aug. 30. The next day, Tibau defeated Varner via unanimous decision, improving his UFC record to 13-7.

"He was around 181 on fight night," says Bittar. "This recovery is controlled, so we get him on a weight that won’t affect his performance, but it can change depending on his opponent."

The heavier the better? Not exactly.

"We never try to get him the heaviest possible on fight night," he says, "because we’ve been through situations in the past where he was very swollen due to excess serum sodium and its weight was almost 186, and this has negatively affected his movement inside the cage."

Losing 20 pounds in four days isn’t easy, but the American Top Team trainers reveal the secret.

"During the fight week, he works on the technical part with striking coach Luciano ‘Macarrao’ and jiu-jitsu coach Marcos da Matta, but also maintenance the aerobic workouts to help weight loss together with a dietary restriction of solid foods and an increase in fluid intake ranging from six to eight liters per day (distilled water) -- or water with zero percent sodium -- for a period of two days after gradually reducing the water," Dias said. "This causes the body to eliminate more water and not retain anything in the moments prior to weighing."

As soon as Tibau hits the scale at 155, he starts to get the water back into his body.

"After this brief recovery, he eats light food which is quickly absorbed, like bananas, grapes, fruit salad, as well as Vitamin Water or Gatorade," Dias says. "The weigh-in usually occurs late into the night and the athlete is already semi-recovered. We continue with the intake of low-fat foods that are rich in carbohydrates every two hours, and also make shakes with added glutamine, dextrose, maltodextrin and vitamins to obtain a super compensation carbohydrate and assist in performance the athlete. We also add calcium pills, potassium and magnesium due to dehydration to avoid cramps on fight time."

Dias and Bittar explain that Tibau has done this procedure for five years, so he already knows how his body will react to the changes and when it’s time to stop. It’s common to see fighters dehydrate using sauna and hot tubs, but they explain that that shouldn’t be the only way to lose weight.

"We've seen several other athletes losing a lot of weight in a short period only with saunas and hot tubs and it really hinders the recovery of the athlete and makes some athletes faint," Bittar says. "In fact, the sauna is very dangerous to health. We will quote a recommendation from the American College of Sports Medicine: 'you should never dehydrate an athlete for more than six percent of their body weight to not affect his performance. When the athlete loses more than 10 percent of his body weight with fluids only (dehydration), your chances of death are very high.'"