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:🔥 THE MAT DOESN’T LIE.ONE HOUR.NO EXCUSES.NO QUITTING.NO HIDING.Tonight, the warriors stepped on the mat a...
09/12/2026

🥋 SENSEI SAYS:

🔥 THE MAT DOESN’T LIE.

ONE HOUR.
NO EXCUSES.
NO QUITTING.
NO HIDING.

Tonight, the warriors stepped on the mat and FREE ROLLED HARD.

We fought for position.
We hunted submissions.
We defended.
We got caught.
We escaped.
We learned.
We pushed each other to the limit.

THAT’S HOW YOU GET BETTER.

You don’t improve by talking about fighting.

YOU IMPROVE BY FIGHTING.

Every roll makes you tougher.
Every mistake teaches you.
Every submission humbles you.
Every round makes the team stronger.

And through it all…

WE TRAIN HARD.
WE ROLL HARD.
WE HAVE FUN.
WE GET BETTER TOGETHER.

🔥 GREAT JOB, WARRIORS!

RESPECT • DISCIPLINE • STRENGTH • HONOR • FAMILY



13

When is it too late to start boxing? My opinion: never.​Whether you’re 18, 35, or 60+, the heavy bag doesn’t care about ...
09/12/2026

When is it too late to start boxing? My opinion: never.

​Whether you’re 18, 35, or 60+, the heavy bag doesn’t care about your birth year.

Boxing isn't just about stepping into a ring to fight; it’s about sharp footwork, discipline, full-body conditioning, and building genuine confidence from the ground up.

​Your journey starts the day you decide to lace up the gloves.

​How old were you when you threw your first punch? Drop your age in the comments 👇

09/11/2026
SENSEI SAYS:🥋 OUR FULL CONTACT KARATE LINEAGE 🥋These pictures are very personal to me because they represent where I com...
09/10/2026

SENSEI SAYS:

🥋 OUR FULL CONTACT KARATE LINEAGE 🥋

These pictures are very personal to me because they represent where I come from, who I have learned from, and the lineage that I have had the honor and responsibility of carrying forward.

In the first picture, Hanshi 10th Dan Isao Ichikawa is with his student, Renshi Luis Zavalza Reyes—my Sensei. In the second picture, my Sensei Luis and I are together as he presents me with my 3rd-Degree Black Belt.

Looking back at that moment from where I stand today as a 5th-Degree Black Belt, I realize even more deeply that the belt itself was never the most important part. What matters is the knowledge, experience, discipline, and responsibility that come with every step along the way.

When I look at these photographs, I see a connection between generations of martial artists—a connection built on dedication, respect, training, and the commitment to preserve Full Contact Karate.

I am proud to be part of that lineage.

What my Sensei received from his Sensei was more than a collection of techniques. It was a foundation, a fighting system, and a way of understanding the martial arts, earned through years of training. That knowledge was passed to me, and now, as a 5th-Degree Black Belt, I feel an even greater responsibility to protect it, continue developing myself within it, and pass it forward to those who come after me.

I want to keep our Full Contact Karate as close as possible to its original techniques and foundations—the real knowledge of stand-up fighting: punches, kicks, knees, elbows, footwork, distance, timing, conditioning, combinations, defense, strategy, and the small details and secrets that can only be truly understood through years of hands-on training and competition.

Those things should never be forgotten.

Generations will change. Training methods may evolve. Students will come and go. But the foundation, principles, and fighting spirit must remain strong.

I am only one link in a chain that began long before me. I respect those who came before me; I value what my Sensei taught me, and I feel a responsibility to make sure that what was entrusted to me continues to move forward.

I am grateful to Hanshi Luis Zavalza Reyes for his guidance, his teaching, his trust, and for being an important part of my journey.

Today, as a 5th-Degree Black Belt, I understand that my responsibility is not simply to wear the rank.

My responsibility is to carry the knowledge.
Protect the foundation.
Honor the lineage.
And pass it on.

🥋 From Sensei to student.
From generation to generation.
From the past, through the present, and into the future.

This is more than the martial art I practice.
This is the lineage I was entrusted to carry. 🥋

For a full biography, click on the link:
https://mmaunderground.info/stand-up-fighting-lineage



13

SENSEI SAYS:OUR JUJUTSU LINEAGE — CARRYING THE LEGACY FORWARDWhen I look at these two pictures, I see much more than pho...
09/09/2026

SENSEI SAYS:

OUR JUJUTSU LINEAGE — CARRYING THE LEGACY FORWARD

When I look at these two pictures, I see much more than photographs. I see a connection that reaches across generations.

In the first picture is Sensei Masahiko Kimura with his student, Sensei Daniel F. Hernandez. In the second is my Sensei, Daniel, and me.

Being part of this lineage is something I carry with great respect and responsibility. What was once passed from Sensei Kimura to my Sensei was not simply a collection of techniques—it was a way of understanding the art, its principles, its foundations, and the spirit behind them.

Today, I have the privilege of receiving that knowledge and becoming another link in that same chain.

My responsibility is not to change what was given to me just for the sake of change. It is to understand it, preserve its essence, practice it honestly, and pass it on. At the same time, every generation has its own time, its own challenges, and its own way of growing. The art continues to move forward, but its roots remain firmly connected to where it began.

That is what makes lineage so important to me.

I am not the beginning, and I will not be the end. I am simply one part of a story that was started long before me and will continue long after me.

From Sensei to student.
From one generation to the next.
Keeping the foundation alive while carrying the art forward.

I am proud to be part of this lineage, and even more proud to have the responsibility of helping it continue. 🥋

For a full biography, click on the link:

https://mmaunderground.info/ground-fighting-lineage



13

I liked the last interview, at 11:30 min, so true
09/09/2026

I liked the last interview, at 11:30 min, so true

I trained Jeet Kune Do like Bruce Lee with Sifu Singh. Eye jab, sid...

🥊 SENSEI SAYS:THE HEAVIEST WEIGHT IN THE GYM IS THE FRONT DOOR.You want to get stronger?WALK THROUGH IT.You want to beco...
09/08/2026

🥊 SENSEI SAYS:

THE HEAVIEST WEIGHT IN THE GYM IS THE FRONT DOOR.

You want to get stronger?
WALK THROUGH IT.

You want to become a fighter?
SHOW UP.

You want results?
EARN THEM.

Nobody cares how tired you are.
Nobody cares about your excuses.
Nobody cares if you feel like training.

THE FIGHT STARTS THE SECOND YOU DECIDE NOT TO QUIT.

Some days you’ll feel strong.
Some days you’ll feel like getting your ass kicked.

SHOW UP ON BOTH DAYS.

Because champions aren’t built when it’s easy.
They’re built when their body says STOP…
and their mind says:

ONE MORE ROUND.

🔥 OPEN THE DOOR.
🥊 STEP ON THE MAT.
đź’€ LEAVE YOUR EXCUSES OUTSIDE.
⚔️ PUT IN THE WORK.

NO SHORTCUTS. NO EXCUSES. NO QUIT.

TRAIN LIKE A WARRIOR.
LIVE LIKE A WARRIOR.
FIGHT LIKE A WARRIOR.



13

SENSEI SAYS:COME TO MMA Underground AND ENJOY THREE FREE CLASSES1. MUAY THAI BAGS & PADS WORKOUT2. KIDS MMA3. BOXING4. K...
09/08/2026

SENSEI SAYS:

COME TO MMA Underground AND ENJOY THREE FREE CLASSES

1. MUAY THAI BAGS & PADS WORKOUT
2. KIDS MMA
3. BOXING
4. KETTLEBELL STRENGTH TRAINING
5. MMA STAND-UP FIGHTING
6. NO-GI JUJUTSU
7. WRESTLING

FOR THE CLASS SCHEDULE, CLICK ON THE LINK
https://mmaunderground.info/class-schedule

-THE WAY OF THE WARRIOR-



13

🥊 ATTENTION, WARRIORS! 🇺🇸MMA UNDERGROUND WILL BE CLOSED ON LABOR DAY — MONDAY, SEPTEMBER 7TH.Take the day to relax, rech...
09/06/2026

🥊 ATTENTION, WARRIORS! 🇺🇸

MMA UNDERGROUND WILL BE CLOSED ON LABOR DAY — MONDAY, SEPTEMBER 7TH.

Take the day to relax, recharge, and spend some quality time with family and friends. You’ve earned it! 💪

We’ll be back in the gym Tuesday, September 8th, ready to get back to work and keep the grind going! 🔥

Enjoy the holiday, Warriors!
REST • RECOVER • RECHARGE • RETURN STRONGER

🥋 MMA UNDERGROUND

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

Alerts

Be the first to know and let us send you an email when MMA Underground posts news and promotions. Your email address will not be used for any other purpose, and you can unsubscribe at any time.

Contact The Business

Send a message to MMA Underground:

Shortcuts

Share