What are the 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

MMA Underground, 835 Virginia Road Ste C, Crystal Lake, IL (2026)

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.

06/19/2026

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

06/12/2026

SENSEI SAYS:
頑張る
GANBARU
DO YOUR BEST

But its true meaning runs deeper. It is the unwavering decision to keep moving forward when every part of you wants to stop.
Anyone can make progress when conditions are favorable. It is easy to advance when the road is flat, the weather is clear, and energy is abundant. The real test begins when the climb becomes steep, when fatigue settles into your muscles, and when doubt starts whispering that you've gone far enough.

This is where Ganbaru lives.

Ganbaru is digging your heels into the earth and refusing to give up ground. It is not driven by motivation, inspiration, or temporary bursts of intensity. Those things come and go. Ganbaru is something stronger. It is discipline. It is resolve. It is the quiet commitment to take one more step when the next step feels impossible. A stone wall is not broken by a single powerful strike. It falls because of thousands of deliberate blows delivered over time. The same is true of any meaningful goal. Success is rarely the result of one extraordinary effort. More often, it belongs to those who continue swinging the pickaxe long after others have put theirs down.
The obstacle before you is temporary. The pain is temporary. The struggle is temporary. But the strength you build by enduring them can last a lifetime. Do not wait for the path to become easier. Do not wait for perfect conditions. Do not wait until you feel ready.
Harden your spirit. Strengthen your frame. Embrace the friction that others avoid. When exhaustion arrives, keep moving. When doubt appears, keep moving. When the weight feels heavy, carry it anyway. Stand firm. Endure the struggle. Outlast the resistance.

Ganbaru. One more step. Then another. Then another.

-THE WAY OF THE WARRIOR-

13

06/10/2026

Sensei Says:

Massive congratulations to our 14-year-old Jose Arreguin, the unstoppable force who clinched victory at the Summer Junior Olympics in boxing! 🥇 Every jab, every hook, every drop of sweat in training led to this well-earned triumph. Jose, your heart, skill, and determination have truly set you apart—what an incredible moment for you and everyone cheering you on!

Huge props to Coach Dylan Kowalski, the ultimate cornerman and mentor. Your guidance, strategy, and calm confidence in the corner helped Jose perform at his absolute best. Every champion needs a coach who can see the fight inside and out—and Dylan, you nailed it.

A special shoutout to Jose’s teammates, whose encouragement, sparring sessions, and unbreakable support created the foundation for this victory. Boxing isn’t just about fists—it’s about community, and Jose’s team delivered every single time.

And let’s not forget the powerhouse behind the power—the Beast boxing program at Underground Boxing! This program builds champions through world-class training, relentless discipline, and a culture that pushes athletes to exceed their limits. Jose’s win is a shining example of the excellence this program cultivates.

Jose Arreguin, you’ve made history, inspired your peers, and shown the world what dedication looks like in action. This is only the beginning—keep punching, keep shining, and keep making us all proud! 🥊💥

06/08/2026

Sensei Says:

Congratulations to Jose Arreguin on an outstanding victory in the ring! Your hard work, discipline, and dedication paid off, and this win is a testament to the countless hours you've invested in your training.
Special congratulations go to Coach Dylan Kowalski for the exceptional job he did in the corner. Your guidance, preparation, and leadership helped pave the way for a successful performance and showcased the importance of having a great coach behind every great fighter.
We also want to recognize Underground Boxing for providing what many consider the best "Beast" teaching curriculum. The commitment to developing skilled, disciplined, and confident athletes continues to produce champions and inspire everyone who walks through the doors.
Finally, a heartfelt thank you to all the teammates who support Jose every day. Whether through training, encouragement, advice, or simply showing up and believing in one another, your support plays a vital role in every success. Victories like this are never achieved alone—they are the result of an entire team working together.
Congratulations to Jose, Coach Dylan, Underground Boxing, and the entire team on a well-earned victory. The future is bright, and this is just the beginning of even greater accomplishments ahead.

https://www.facebook.com/share/v/1Bf3ScP1Ah/

06/07/2026

SENSEI SAYS:

正勝吾勝
Masakatsu Agatsu
Victory over oneself

True victory is not defeating another person—it is defeating the doubts, fears, and limitations within yourself.
Every day presents a choice: remain who you were yesterday or become stronger than you were before. The greatest battles are often invisible, fought in moments of discipline, perseverance, and courage.
When you choose action over excuses, growth over comfort, and resilience over surrender, you embody the spirit of Masakatsu Agatsu.
Do not measure your progress against others. Measure it against the person you were yesterday. Every step forward, no matter how small, is a victory.
Master your mind. Strengthen your character. Honor your path.
True victory is self-mastery.

正勝吾勝
Masakatsu Agatsu
Victory over oneself

-THE WAY OF THE WARRIOR-

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

Website

http://mmaunderground.info/

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