Mark Munoz planned retirement on day he signed his UFC contract

The day Mark Munoz signed his first UFC contract he already knew that his career had an expiration date attached to it.

Now, every fighter at some time or another reaches a point where retirement is the only option left on the table. Nobody stays young forever.

But for Munoz when he joined the UFC in 2009, he promised his wife and children that he would set goals for himself and a time limit on how long he would experiment with MMA before turning his attention back to them full time.

"The idea of retirement came at the start of my UFC career. I told my wife, 'I'm going to quit coaching and I'm going to get into MMA'. She said 'why are you doing that?'. I explained why and promised her when my daughter gets to the first grade, I will retire from fighting," Munoz told FOX Sports recently. "That was six years ago. My daughter has been in the first grade for the whole year this year.  Obviously the year I had last year with all the injuries and the adversity I was going through, I think it was induced by a lot of stress in my life, I had a lot of plates spinning and there was just a lot going on in my life.

"It was just time to take away some of the stresses that were hurting me health wise."

Munoz will officially call it a career following his next fight this Saturday against Luke Barnatt at UFC Fight Night from the Philippines. The decision to retire may have happened six years ago, but Munoz can't deny that the desire to compete is a fire that will likely never be extinguished.

He had to think long and hard about the decision to retire because striving to win is something he's had ingrained in him for as long as he can remember. Munoz has seen how so many professional athletes struggle to walk away even when the time is right, but he was forced to look at the bigger picture when finally making the call to retire after just one more fight.

"I've been a competitor my whole life. I even compete against my wife for a spot on the couch. I compete when we leave the grocery store, we race to the car to see who gets there first. I'm a competitor at heart. I love competing at all things. Just in me, even when I was coaching in college, it was hard for me because I wanted to be out there competing," Munoz said.

"So it's definitely part of me but I truly believe this is a new chapter in my life. I can compete in other ways. I want to leave my legacy in other ways. I want to be a good dad and a good husband to my family."

The original deal Munoz cobbled together with his wife came to fruition in large part because of his youngest daughter, who is now in the first grade, but the wake-up call about the time he spent away from his family actually came from his eldest child.

Munoz's oldest daughter only has a couple of years left at home before she's off to college, and he realized recently just how much of her life he's missed by fighting, training to fight and spending time building his gym, Reign Training Center.

"These last six years, my daughter has been growing up before my eyes and I've missed special moments and that's hard for me to even think about," Munoz admitted. "Because I want to be there and I wasn't there. I don't want to make that mistake with my kids so there's a lot of catching up to do with my oldest daughter.

"For me family is the most important thing. It's definitely time for me to start a new chapter."

To accomplish his goal, Munoz not only decided to stop fighting but he also closed down the gym he opened that housed dozens of top named UFC competitors over the years from Michael Bisping to Patrick Cummins to Brendan Schaub to Jake Ellenberger.

Reign Training Center became a hub for top mixed martial artists ever since Munoz founded the gym in 2010, but he also found out that during the past five years he became the heart and soul of everything that happened inside.

He was the head coach. He was the wrestling coach. He was the business owner. He was the person everybody looked to for answers.

To keep the gym running like a well-oiled machine, Munoz spent day and night there making sure that the facility was on point with everything happening from the beginners courses to the professionals getting ready for fights in the UFC.  When he decided to retire with his upcoming fight on Saturday, Munoz realized that his life still wouldn't change very much if he was still spending 12 and 13 hours a day at the gym.

So he closed the doors at Reign one last time and said no more.

"It was bittersweet. I was very hurt. There was a span of about three days where I was very emotional. After seeing all the guys coming through and all the women and children coming into the gym and I just announced we were closing and I just saw tears all over the place," Munoz said. "I'm still getting emotional even talking about it. There were times I couldn't even go in the gym because I'd see people in the gym and they'd give me a hug with tears in their eyes.

"It hurts my heart. It was a hard decision but it was a decision that needed to be made for me and my family. I tried making it work and it just didn't work out.  I'm keeping Reign, the name, I'm not selling it just shutting the doors. I'm not selling it, let me get that straight. I'm just shutting the doors for right now."

After his fight is over on Saturday -- win, lose or draw -- Munoz will officially retire from the sport and he promises there will be no going back. He plans to return to coaching wrestling, which was his first competitive passion, while still working with community outreach programs like the anti-bullying campaign he's spearheaded for the past couple of years.

Most importantly, Munoz will go back to being a full-time husband and father because 25 years from now he'll always remember his biggest wins and losses inside the Octagon, but the memories he'll share with his wife and kids will far exceed anything he could ever accomplish as a fighter.

"It's been really hard for me, especially these past six years being an owner and operator of Reign Training Center, spending time at the gym, and then being a UFC fighter on top of everything with training, traveling, all my sponsor engagements and then my community involvement. It was a lot of time," Munoz said.

"Right now, I just want to prune my tree so I can be more fruitful in other places. I definitely want to put my family at the forefront."

Make sure to watch Munoz in his final fight along with the rest of the card at UFC Fight Night: Edgar vs. Faber this weekend with coverage starting at 7am ET on FOX Sports 1 and the main card for the fights kicking off at 10am ET.