Picture Holly Holm, one of the UFC's newest female fighters, sitting in a sweat suit on the top shelf of a sauna.

Sweat pours down her face. Sometimes she or her teammates will bring bags of ice into the sauna just to cool her head. The purpose? To help her stay in there longer. She needs the weight gone now.

Holm is just one of a huge number of MMA fighters playing a potentially dangerous weight game: Dropping enormous amounts of weight in the week leading up to a bout, with the goal of having a size advantage against an opponent on fight night. There are obvious problems with putting the body through such turmoil, and those problems have been popping up more and more in the news, both inside and outside of MMA. Amateur wrestling has a long history of athletes dropping too much weight. Boxers routinely tack on 15-plus pounds between weigh-ins and bouts.

And recently, crash weight-loss has become a UFC headline, too. Renan Barao passed out and had to go to the hospital the night before his headlining fight against TJ Dillashaw on Aug. 30, gutting a major UFC event. The former 135-pound champ plummeted in the UFC hierarchy and now must fight his way back to title contention. And on the first episode of this season's "The Ultimate Fighter," a preview for upcoming episodes showed one female fighter who appears to pass out trying to make weight.

Holm, one of the best female boxers ever, has been cutting weight for years. She has transitioned to MMA and, at 7-0 with name recognition and street cred, is a crucial recent addition to the UFC's women's roster. She's also an example of an athlete pushing her body to extremes as she trains her sights on dethroning UFC champ Ronda Rousey.

Holm is 5-foot-8, with a "walk-around" weight of about 155 pounds. But she will be fighting at bantamweight (135 pounds) when she steps foot into the Octagon for the first time, on Dec. 6. When she talks about making weight, she speaks casually. It's a part of a fighter's life, she says, and it has been a daily thought for Holm for the past decade. She doesn't want anybody to feel sorry for her -- it's part of the deal as a pro fighter.

But the sheer numbers are alarming. Holm feels comfortable if she can be within 10 pounds of her weight class the day of the weigh-in. That means she has to lose 10 pounds -- in 24 hours.

The sauna is a quick solution, generating massive amounts of heat and sweat. But the sauna is also an example of an unscientific rapid weight-loss process that experts say is incredibly dangerous for the human body. Especially for female fighters.

ESPN analyst Dr. Mark Adickes, who previously served as the team physician for the Houston Rockets and the U.S. ski team, said quick weight loss for female athletes who already maintain such a low body-fat percentage can put them at risk for long-term repercussions. "Fat cells produce estrogen, which is necessary for females to maintain healthy bone density and strength," Adickes said.

That kind of drop also can begin to impact women's menstruation cycles, and female fighters often complain about retaining water. "At that time, your hormones are doing completely different things," Holm said. "It's so unpredictable. But your body just naturally keeps that water. There are definitely things that make it harder for females, but that's not an excuse. If you sign up for a fight, you have to make weight. Otherwise fight at a higher weight class. It's that simple for me."

Felice Herrig, a contestant on Season 20 of "The Ultimate Fighter," is among the group of competitors vying to be the UFC's first 115-pound (strawweight) champ. Most of the women in the house are dropping at least a few pounds to get to 115. "I don't cut that much water weight," Herrig said. "So I eat really healthy year-round, and I'm never really far from weight. I don't have a lot of body fat anyway. But it's a lot of trial and error of what diet works for your particular body."

That trial and error can be problematic. Most rapid weight-loss is handled individually, with fighters, wrestlers and even horse jockeys figuring out on their own how to cut down. Often there is little or no medical supervision.

Saunas are a popular go-to method for fighters. Others employ the Epsom salt bath method to draw out toxins and pounds. "I never liked using Epsom salt baths, though," Holm said. "I'd sit there forever and lose maybe one or two pounds. I'd rather sit in the sauna where I knew I could lose more weight. It also seems that guys just sweat more. But I've always been one of the fortunate ones -- as a female I do sweat really well."

UFC star Anthony Pettis, one of the coaches on TUF 20, also is not a fan of the salt bath. "The bath weight cut -- I hate that thing," he said. "That's what happened with Renan Barao [at UFC 177]. He was in the bath, got lightheaded and fell. I mean it works, you can drop weight quick and it's easier than the sauna, but you can get lightheaded. The bath is so hot and you're losing all this weight ... you just pass out."

The repercussions of constant weight loss aren't just physical, either. Rousey has talked before about how dropping weight played a part in her developing bulimia. Herrig says she fell into a dangerous mindset at one point in her career. She worried constantly about maintaining and making weight, and that preoccupation turned into something darker. "I've always been really healthy, but there was a point in my career where I got so worried about making weight, psychologically you develop body dysmorphia and eating disorders because of it," Herrig said. "You're thinking 'Oh, that's too much or I can't eat that.' I'm in a good place now, though."

According to McCallum Place, an eating disorder center, athletes in combat sports may be particularly susceptible to disordered eating because of the nonstop weight yo-yo of their professions. And this can put athletes into the scary cycle known as the female athlete triad: disordered eating and inadequate calorie consumption overall can result in a disrupted menstrual cycle -- and both of these health concerns then decrease the athlete's overall bone density, resulting in stress fractures and broken bones.

"I have a patient who is an elite athlete but she had repeated stress fractures and she hasn't been able to compete in three years," Adickes said. "She's so lean, she's not producing enough estrogen to strengthen her bones. So we got some dietitians to help her with proper nutrition. But for any female athlete, the damage can be long-term. You've got to train hard, but train appropriately to what your body can take."

UFC VP of regulatory affairs Marc Ratner has said in the past that rapid weight loss is an important issue to be addressed. But he's also referenced the ingrained culture that fighters, trainers and doctors around MMA all describe when they talk about what should be done: These are adult, professional athletes who decide to drop weight and, for the most part, do so without issue. It's been a part of the fight game forever, and may always be. How much can the UFC really do?

The reality may be, not much, other than increased education about the ramifications of cutting weight. Helping athletes minimize the risk during cuts may be another option.

One technique that Holm uses is to make sure she never does a major weight cut by herself. All along the way, when she or a female teammate at Greg Jackson's MMA camp in Albuquerque is trying to make weight for a fight, it's with a team of supporters -- both to help with the mental battle as well as to keep an eye on her, physically. "The girls all just come together and never let anyone go through the process alone," Holm said. "This job is hard. Half the struggle is just making weight. I don't know anyone who thinks it's fun. But we try to look out for each other. Teammates make it so much more bearable."