Mike and Karen Valentine are true examples of people who work to improve their professional skills and live their personal values more than almost anyone you could hope to meet.

PMA Black Belt

Mike Valentine

Founder, co-owner 6th Dan

Hi, I am Mike Valentine. I am the founder, co-owner and head instructor of Practical Martial Arts, formerly Marin Karate Kids. I am a sixth degree black belt under Dave Kovar and a BJJ Black Belt under Clovis Silva. I have been actively training in martial arts for over 40 years.

I started martial arts in Falls Church, Virginia. I was one of those very young six year olds. I was the kid whose belt falls off, fingers are in his mouth and whose focus is everywhere but where it should be. I was asked to leave in order to mature a little bit. I returned at age nine and have been training ever since. I spent the better part of my youth competing in tournaments, watching kung fu, and waiting for my mystical Bruce Lee powers to appear. Point fighting lead to full contact which in turn lead to several years competing in amateur boxing. I attended San Fransisco State University, College of Marin and U.C. Berkeley studying Psychology and Sociology.

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In 1996 I met and fell in love with Karen; we run the dojo together as a team. We have two boys, Milo and Levi, who fill our lives with love and challenges. Boy, did that bring us an all new level of empathy for the parents in my school!

My training over the last four decades has been extremely varied, competing in amatuer boxing, training in Muay Thai, Judo, Tae kwon do, Kenpo Karate, Jeet Kune Do, Wing Chun, Judo, wrestling and over the last decade+ my focus has been on competing in Brazilian Jiu Jitsu and submission wresting. I won the IBJJF Master- Senior 2010 No Gi World Championship, Senior 3 division, with gold medals in the Middle weight devision and open category. I have won gold in the 2009 Copa Pacific, and silver in the 2009 American Nationals, trained under Eduardo Rocha and David Meyer and earlier under Caesar, Charles and Ralph Gracie.
In 2013 I earned my BJJ Black Belt from and am currently training with Clovis Silva. I am extremely lucky to have this truly balanced, well evolved human being as my teacher. Clovis is a phenomenal jiu jitsu player, a great coach, and an exemplary example of what a master instructor should be.

I feel blessed to have trained under many other great coaches and instructors and wish to thank those mentioned above as well as Jim McGowan (Greco-Roman Wrestling and Judo), Jon Sutherland (Kenpo Karate), Mark Foster (Kenpo Karate), Roger Carlon (Tae Kwon Do), Daython Taylor (American Karate), Joe Burke (Boxing), Colt Dickey (Submission Fighting), Oliver Reich (Brazilian Jiu Jitsu), Steve Labonty (American Kenpo), Terry Neill (Kenpo Karate), Jeff Dix (Kenpo Karate), Guy Chase (Submission Wrestling), Derek Weinstein (Wing Chun), Rickson Gracie (One private lesson and two seminars that showed me what a true master is) Newton Pinto (Brazilian Jiu Jitsu), Hakim Boudrir (Muay Thai), Kurt Osiander (Brazilian Jiu Jitsu), Terry Gibson (Jeet Kune Do Concepts), Tom Callos (Ultimate Black Belt Test) and John Will (Brazilian Jiu Jitsu and Street Self Defense) for their support and incredible technical knowledge.

Karen Valentine

Co-owner, 3rd Dan

Karen began training in 1996 after her future husband, Mike, broke her skepticism of martial arts. She originally misunderstood martial arts as being either violent or just goofy. But after training with Mike at PMA and later in Muay Thai and Brazilian Jiu-jitsu, she was hooked. It was the first time she felt physically empowered and motivated. She quickly realized that there’s more to it than just punching and kicking, and believes in the martial arts’ ability to change people for the better. Karen enjoys stand-up but especially loves grappling. She earned her first Black Belt in 2002. She earned her 2nd degree under Tom Callos with the Ultimate Black Belt Test in 2006 and her 3rd degree in 2012.

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Karen’s background is originally in education. She graduated with honors from San Francisco State University with a degree in Art Education. Later, she returned to school at Dominican University to earn a Multiple Subject Teaching Credential. She’s taught Fourth Grade, Health Education to Teens, HIV/AIDS education to college students, sculpture & ceramics to middle school kids, child abuse prevention to elementary school children and worked as a “Buddy” to young kids having difficulty adjusting to school. This background has been a perfect compliment to husband and business partner Mike’s wide-ranging martial arts history. Karen’s role at the dojo is Program Director, Marketing and Self Defense Instruction.

In her ‘spare’ time, Karen enjoys hiking with Mike, their two boys and their little dog Po. She has been slowly developing her Nature’s Dojo program with dreams of getting more children outdoors learning ‘the way of nature’.

“I love running the dojo with Mike, for the past 20 years not only because it has afforded us such a wonderful lifestyle but because I truly feel that the dojo is a creative outlet, a metaphor for life. What we produce in the dojo, we have produced for society.” ~Karen Valentine 2006

Patti Oji

3rd Dan
Student Manager & Instructor

Ms Patti is PMA’s most long term staff member. She found the dojo when her boys were young (18 years ago) and she was looking for an outlet for their exuberant energies. As the boys progressed and she spent half her week at PMA anyway, she decided to give it a try herself. She was immediately hooked and eventually earned a first, second and third degree PMA black belt as well as her blue belt in BJJ. Her second degree was under Tom Callos and the Ultimate Black Belt Test. This incredible experience took her to Alabama for 5 years in a row to help build homes for the very, very needy. She is currently pursuing her fourth degree studying GoJu Shorei Karate & Weapons.

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Before she joined the PMA family, Ms Patti was a freelance graphic designer and an aerobics instructor. In her spare time, Ms Patti enjoys road cycling, yoga, her studies as an aromatherapy student and especially her enormous success as a representational style oil painter. Be sure to check out her work: http://patriciaoji.com

Aaron Phelps

3rd Dan, Main Instructor

Mr Phelps started training in Martial Arts at age four.  He earned is first black belt in Kajukenbo under Eddie Solis, Owner of Solis Martial Arts in Hercules.  Following his training in Kajukenbo, he continued his training in competitive Muay Thai Kickboxing.  His primary coach responsible for progress in Muay Thai was Ra Karma Young, owner of CMT Athletics in Oakland. Most recently in 2013, he earned his 3rd Dan at Practical Martial Arts and his Brazilian Jiu-Jitsu blue belt under Mike Valentine.
Mr Phelps started teaching at 11 years of age.  In addition to his martial arts career, he has a BS degree in business with a marketing option.

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After college, Mr Phelps started a career in fitness after becoming a certified trainer under the National Academy of Sports Medicine.  Holding roles in customer service, trainer, and fitness management, he learned his passion was and always be Martial Arts and coaching.  As an instructor at PMA, Mr Phelps goal is to cultivate student development in confidence, structure, athletics and transferability of black belt principles to everyday life.

David Schimmel

1st Dan, Instructor

Mr. Schimmel is 22 years old from Santa Cruz, California and joined the Practical Martial Arts team in 2015. He started training martial arts in 2000. He holds a 3rd degree black belt in the art of Ho Kuk Mu Sul back that he earned in June of 2012.

Mr. Schimmel competed in many local TaeKwonDo tournaments around the Bay Area. His most memorable competition was when he won gold in Jeju, South Korea in the heavyweight division.

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After leaving a busy head instructor position in Santa Cruz he moved to Mill Valley where he first coached gymnastics (holding a USA Gymnastics cert) but then felt compelled to teach martial arts again. We are lucky to have him with us!

Mr Schimmel is going to school full time and COM studying Business Management. His other hobbies include extreme Mountain Biking, Snowboarding, Surfing.

Ruki Yee

3rd Dan, Instructor

Rob Potter

3rd Dan, Instructor

As a child of the 70’s, Rob’s interest in marital arts was first piqued after watching David Carradine in Kung Fu. After years of informal training in his backyard, which mainly consisted of making slicing noises and flailing his arms and legs around vigorously, he started studying Tae Kwon Do and competing in Olympic sparring. After earning his purple belt in TKD, Rob dabbled in aikido before getting hooked on Freestyle Martial Arts and BJJ at Practical Martial Arts. Rob earned his purple belt in Brazilian Jiu Jitsu and his second degree PMA Black Belt under Mike Valentine.

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When Rob is not training or teaching at the dojo, he is a middle-school mathematics and geography teacher at Mount Tamalpais School. He enjoys mountain biking and backpacking, and is involved in fundraising efforts for pediatric cancer research and Make-A-Wish.

Rob is joined at the dojo by his two sons, Samuel and Kasper.