MMA Underground

MMA Underground MMA, Kettlebells, and full-body conditioning MMA UNDERGROUND INC. Along with kettlebell and Xtreme Cage Fighter Workout classes
(498)

is a training ground and fitness facilty for students who want to get into the best possible physical shape. The center is helmed by head coach Oscar Olivares Sensei, who brings with him a long list of achievements and venerable lineages in both stand-up fighting and ground fighting. Oscar Sensei believes that anyone can achieve their fitness goals, be they weight loss, muscle gain, or competitive

fighting readiness, if the drive to succeed is there. So, he fuel this drive in a spacious Mixed Martial Arts facility, where clients will find a padded floor, hanging bags, and dummies waiting to punched, kicked, and jabbed during group classes or personal training sessions.

Sensei Says:Fifteen years ago, this picture captured more than the first fighting team of MMA Underground. It captured t...
08/16/2026

Sensei Says:

Fifteen years ago, this picture captured more than the first fighting team of MMA Underground. It captured the beginning of a vision.
When people look at this photo, they see young fighters. I see something much bigger. I see years of discipline, sacrifice, hard work, and lifelong friendships. I see men who learned that true strength isn't measured by how hard you can punch or how many fights you win—it's measured by your character, your integrity, and how you treat others.

For the past 15 years, our mission has never been just to produce fighters. Our mission has been to build good men—men with strong morals, respect for others, love for their country, loyalty to their families, and the courage to stand for what is right. We believe martial arts should make you a better person before it ever makes you a better athlete.

Many of the people in this photo have gone on to become fathers, husbands, professionals, military members, business owners, and leaders in their communities. That is the greatest victory any coach could ever ask for.

At MMA Underground, we don't just teach punches, kicks, wrestling, or submissions. We teach discipline. We teach responsibility. We teach humility. We teach perseverance. We teach respect. These values stay with you long after you leave the mats.

If you're looking for a place where you can become stronger—not only physically, but mentally and morally—we invite you to join our family. Whether your goal is self-defense, competition, fitness, or simply becoming the best version of yourself, there is a place for you here.

Come train with us. Build confidence. Build discipline. Build character. Build a better life.

MMA Underground—where champions are built from the inside out.

08/10/2026

For as long as I can remember, martial arts have been a part of my life. When I founded MMA Underground, my vision wasn’t to create just another gym—it was to build a place where people could train with purpose, challenge themselves, and become stronger in every aspect of life.

MMA Underground is more than a fight gym. It’s a community where beginners train alongside experienced athletes, where respect comes before ego, and where every person is encouraged to improve at their own pace. Whether your goal is self-defense, fitness, competition, confidence, or simply becoming the strongest version of yourself, you’ll find a place here.

Our students come from every background. Some walked through our doors without ever throwing a punch or learning a takedown. Others have years of experience in martial arts. What unites everyone is the desire to learn, work hard, and support one another.

As summer comes to an end and new routines begin, now is the perfect time to invest in yourself. Build confidence. Improve your conditioning. Learn real-world self-defense. Push beyond your limits while training in a positive, disciplined environment.

Come meet our coaches, tour the academy, watch live training demonstrations, and experience 3 FREE MMA classes for yourself.

There are many great martial arts schools in our area, and we respect them all. At MMA Underground, we’re proud of the family we’ve built and the warriors we’re helping develop every day.

Come experience the difference.

🥋 Train Hard. Fight Smart. Never Quit.

13Sensei Says:WARRIORS WANTED.Comfort never built a fighter.Our No-Gi Ju-Jutsu team is growing, and we're looking for pe...
07/30/2026

13
Sensei Says:

WARRIORS WANTED.

Comfort never built a fighter.

Our No-Gi Ju-Jutsu team is growing, and we're looking for people ready to push their limits.

🔥 Learn to dominate the ground.
🔥 Build relentless conditioning.
🔥 Develop real confidence through real training.
🔥 Train side by side with champions.

No excuses. No shortcuts. Just hard work, discipline, and the will to improve every time you step on the mat.

Claim your 3 FREE classes and prove to yourself what you're made of.

Don't watch champions. Train with them. Become one.

Sensei Says:WARRIORS WANTED.Comfort never built a fighter.Our No-Gi Ju-Jutsu team is growing, and we're looking for peop...
07/30/2026

Sensei Says:

WARRIORS WANTED.

Comfort never built a fighter.

Our No-Gi Ju-Jutsu team is growing, and we're looking for people ready to push their limits.

🔥 Learn to dominate the ground.
🔥 Build relentless conditioning.
🔥 Develop real confidence through real training.
🔥 Train side by side with champions.

No excuses. No shortcuts. Just hard work, discipline, and the will to improve every time you step on the mat.

Claim your 3 FREE classes and prove to yourself what you're made of.

Don't watch champions. Train with them. Become one.

13Sensei Says:Celebrating with the Champion at home
07/29/2026

13
Sensei Says:
Celebrating with the Champion at home

07/26/2026

13
Warriors:

If you couldn't make it out to support Jose yesterday, we've got you covered—here's his full fight.

Make sure you don't miss his next one. Jose always brings the action and leaves it all in the ring!

07/26/2026

Warriors:

If you couldn't make it out to support Jose yesterday, we've got you covered—here's his full fight.

Make sure you don't miss his next one. Jose always brings the action and leaves it all in the ring!

13🥊 Another dominant performance by Jose! 🥊Congratulations to Jose on yet another incredible victory by TKO! Your discip...
07/26/2026

13
🥊 Another dominant performance by Jose! 🥊
Congratulations to Jose on yet another incredible victory by TKO! Your discipline, dedication, and relentless work ethic continue to pay off every time you step into the ring. You represented yourself, your team, and everyone who believes in you with heart and determination.
A special congratulations to Coach Dylan for another outstanding job in the corner. Your calm leadership, smart strategy, and experience guided Jose every step of the way and played a huge role in this victory.
Finally, a heartfelt thank you to all of Jose’s teammates and sparring partners. Champions are never built alone. Every round you pushed, every lesson you shared, and every sacrifice you made in the gym helped prepare Jose for this moment. This victory belongs to the entire team.
The hard work continues—one fight at a time, one victory at a time. On to the next! 🥊🏆💪

🥊 Another dominant performance by Jose! 🥊Congratulations to Jose on yet another incredible victory by TKO! Your discipli...
07/25/2026

🥊 Another dominant performance by Jose! 🥊
Congratulations to Jose on yet another incredible victory by TKO! Your discipline, dedication, and relentless work ethic continue to pay off every time you step into the ring. You represented yourself, your team, and everyone who believes in you with heart and determination.
A special congratulations to Coach Dylan for another outstanding job in the corner. Your calm leadership, smart strategy, and experience guided Jose every step of the way and played a huge role in this victory.
Finally, a heartfelt thank you to all of Jose's teammates and sparring partners. Champions are never built alone. Every round you pushed, every lesson you shared, and every sacrifice you made in the gym helped prepare Jose for this moment. This victory belongs to the entire team.
The hard work continues—one fight at a time, one victory at a time. On to the next! 🥊🏆💪

Address

835 Virginia Road Ste C
Crystal Lake, IL
60014

Opening Hours

Monday 9am - 10am
5pm - 8:30pm
Tuesday 9am - 10am
5pm - 8:30pm
Wednesday 9am - 10am
5pm - 8:30pm
Thursday 9am - 10am
5pm - 8:30pm
Friday 9am - 10am
5pm - 8:30pm
Saturday 10am - 1pm

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