Inside 'The Challenge: Champs vs. Stars' with Olympian Kim Glass and fitness guru Emily Schromm

Olympian Kim Glass and "Challenge" veteran Emily Schromm are featured in MTV's "Champs vs. Stars". Courtesy of MTV

Former volleyball player and 2008 U.S. Olympic silver medalist Kim Glass, 33, stepped off a plane from an overseas vacation to the news that she'd been offered a spot on a reality game show -- and it would start filming in a week.

Her agent had pitched her for "The Challenge: Champs vs. Stars," and to her surprise, MTV wanted her on the series.

"I thought, 'Oh my gosh, am I going to have to eat cow balls?'" Glass said in a phone interview when discussing some of the series' more interesting challenges.

Like its predecessor, "Champs vs. Pros," this season pits past Challenge champions of the show against current and former professional athletes, WWE superstars, television personalities and a former "Bachelor" contestant. All of them are competing in support of their chosen charities.

The thrill of competition combined with supporting causes near and dear to their hearts was enough to lure former Challenge competitors and professional athletes alike back to the proverbial field to compete again.

Glass, who retired from volleyball in 2014, was one such athlete on the Stars' team, along with four-time Olympic medal-winning gymnast Shawn Johnson and former NFL wide receiver Terrell Owens. UFC fighter Michelle Waterson, who is still actively competing, is also a part of the Stars' squad.

On the Champs' side of things, Challenge veteran Emily Schromm, 28, joined the show after a four-year hiatus from the series. Schromm is accompanied by Challenge champions: Chris "CT" Tamburello, Johnny "Bananas" Devenanzio and Zach Nichols. WWE star Mike "The Miz" Mizanin serves as the host.

"It's difficult to disappear for a long time and then come back and film things," Schromm said in a phone interview. "But with what's going on today, I felt the need to do something big. When [MTV] said it was for charity, and it was going to be filmed in the U.S., [joining the show] became a no-brainer for me."

Female empowerment is a cornerstone of Schromm's approach to fitness, so she selected Girls Inc. as her charity of choice. The organization works to inspire girls to be strong, smart and bold through leadership programs and mentoring.

"I wanted to find an organization that did something at a really deep level," Schromm said." Girls Inc. works with girls aged 8 to 18 and what they do is so empowering."

Glass is competing on behalf of Covenant House, an organization that works with homeless youth.

"I was homeless for a while," Glass said. "So I knew that no matter what, I wanted to do something with homelessness and youth."

The Champs' and Stars' teams will be tested on various skills throughout the eight-week season, including things such as strength and agility to determine who will take home their share of the $150,000 for their respective charities.

These challenges are no joke. The first week, the teams competed to see who could pull a semitruck across the parking lot the fastest, and the second week had the competitors chasing each other around a parkour game. Their wins and losses, along with alliances competitors made (or failed to make) will shape the game as the field is whittled down to the finalists.

Historically, women on "The Challenge" have been seen as lesser competitors than their male counterparts. However, Schromm has been one of the women to push back on that narrative consistently. She has reached the final on every season on which she has competed, and she won nearly every daily competition during her most recent season.

"I work out in a way that keeps me prepared for a zombie apocalypse or 'The Challenge' whenever I do it," Schromm said. "I mainly felt nervous, because you never know how you're going to do in these shows. Although my training has been great, I was holding my breath hoping for a lot of athletic challenges because that is the one thing that I knew I'd be good at."

"If you're coming out of retirement for this, you're coming ready to go," Glass said of Schromm. "She's a strong-headed woman, as well as strong physically. She's the best woman on their team."

Glass, on the other hand, might be inexperienced, but the athlete is poised to have a tremendous impact on the game. Her height, 6-foot-3, is nearly unheard of for women on "The Challenge" (except for show alum Laurel Stucky), which puts her in some interesting situations.

"I'm going against guys all the time," Glass said. "Some of our girls were a lot smaller, so sometimes they looked at me as one of the guys. That height difference comes into play when you're playing some of those games."

And although the "Challenge" isn't exactly the Olympic Games, it's hard for Glass not to get excited about the competition.

"It was fun to get those pregame jitters," Glass said. "It was cool just being in a different atmosphere with all of these athletes, but it was hard having a mic on me all the time."

Maybe we'll even see these two face off in an elimination battle. It would be one for the ages.

"The Challenge: Champs vs. Stars" airs on MTV Tuesday nights at 10 p.m. ET.