NIMMA Instructors


Shihan Michael Sartwell - 8th Degree  Black Belt

Shihan Michael Sartwell started training in 1987. He studied at the National Institute of Modern Martial Arts in Claremont, NH under Grandmaster Raymond Gonthier learning an innovative system combining Shorin-Ryu Karate, Jukado, and Arnis Lanada into a singular style. NIMMA was a mixed martial art before the phase was even used. Master Sartwell is the current head instructor and owner of NIMMA, well known for his exciting teaching style. He earned his 8thdegree black belt and Soke-Dai (successor) from Hanshi Ramona Hastings head of Soken Go Kai Do Ryu in 2015. He has years of experience as a competitor in numerous martial arts including karate, stick fighting, Brazilian Jiu-jitsu, judo, and Tae Kwon Do. He demonstrates his comprehensive knowledge of martial arts when teaching, presenting at seminars, and in conversation. In his 15 years studying Judo and Brazilian Jiu-Jitsu he has synthesized a comprehensive approach to the integration of standing and ground based martial arts. Anyone fortunate to participate in one of his seminars will certainly come away with increased knowledge and improved skills in both standing and ground martial arts.

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Shihan Todd Savage - 7th Degree  Black Belt

Shihan Todd Savage, a 7th  degree Black belt, has studied and taught at N.I.M.M.A. For over 22 years. His close attention to detail, and striving for perfection make him a great asset to the students.  He specializes in Arnis (Stick fighting), and has developed this program as well as his Savage Karate Fitness Program.

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Renshi Phillip Kelly - 4th Degree Black Belt

Phil joined the National Institute of Modern Martial Arts in April 2005. Since coming to NIMMA, Phil has achieved the rank of 4th Degree Black Belt.  Phil continually improves his own skills as well as those of his students through stressing the foundation of basics and kata. Phil also takes turns in the adult rotation for both the adult classes held on Thursday. Phil enjoys expanding his knowledge of Martial Arts by reading books on subjects not in the school curriculum, such as Toyama Ryu (sword). NIMMA is definitely a family activity for Phil since both his Son Mitchell (Yondan) and Daughter Cassidy (Sandan) have participated in the program since they were 7 and 5 years old. Phil’s wife Shelly has achieved her 4th Degree Black Belt.

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Renshi Robert Rheume

4th Degree Black Belt

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Sensei Colin Premo - 4th Degree Black Belt
1st Degree American Kenpo

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Sensei Colin started his martial arts experience as a freshman at Westfield State College in 1993 through participation in the Karate Club. Part of the training was in Ed Parker Kenpo taught at the New England Martial Arts Training Center (NEMATC) with Mr. Steve Serwecki and the other was sparring classes taught by a fellow WSC student that was a 2nd Degree Black Belt in Tae Kwon Do. Colin was able to achieve the rank of Purple belt through NEMATC and upon returning to Central Massachusetts discovered Holden Martial Arts. It was here working with Mr. Harry Grimm and his hard working (and hard hitting) team of instructors that he was able to achieve a black belt in Parker Kenpo in 1999. This is also where Colin started teaching classes as a way of giving back to martial arts.
In 2000 Colin moved to Western MA and was introduced to Master Roger Lynch and Ashfield Tae Kwon Do. Colin studied with this talented group of martial artists from 2000-2005 and was able to achieve the rank of Green Belt. Colin assisted Master Lynch with the children’s classes held at Ashfield TKD and benefitted immensely by observing his teaching style. Colin still has many friends at Ashfield TKD and will occasionally attend a Saturday class or to teach a seminar.
In 2008 Colin wondered into the National Institute of Martial Arts on a lunch break and had a discussion with one of the instructors that happened to be there at the time. Since coming to NIMMA, Colin has achieved the rank of 3rd Degree Black Belt and has been teaching classes for the majority of the time here. Colin continues to hone his own skills as well as those of his students through stressing the foundation of basics and kata. Sensei Colin teaches the sparring class for Junior Brown Belts on Wednesday and Thursday and the Junior White belts on Thursday. Colin also takes turns in the adult rotation for both the adult classes held on Thursday. NIMMA is definitely a family activity for Colin since both his sons have participated in the program since they were 3 years old and his wife Michelle is currently working on her 3rd Degree Black Belt.

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Renshi Shelly Kelly   4th Degree Black Belt

Renshi (Polished Instructor) Shelly joined the N.I.M.M.A. Dojo in September of 2008. Teaching has always been a large part of her martial arts journey. She was approximately a green belt when she started assisting Renshi Colin’s child white belt class and soon afterwards when she had received her purple belt she began assisting her husband Renshi Phil by helping teach his junior brown belt class. She then continued to help teach Renshi Colin’s child white belt class and Renshi Phil’s junior brown belt class until she finally took over the teaching position entirely for Renshi Phil’s junior brown belt class. She then decided to take a step back from teaching the white belt class and chose to focus solely on teaching the child adult brown/black belt class which is still her current position at the dojo. She recently received her 4th degree black belt and Renshi title and is currently researching and learning the Eku (oar) kata’s and various exercises to hopefully add in to our main curriculum.


Sensei Isaiah Clogston-4th Degree Black Belt

Sensei Isaiah has been training with NIMMA since the age of six. He has a passion for instruction and tournament-style fighting. During five years of teaching, Sensei Isaiah has taught children, teens, and adults alike with his high-energy, technical approach at the Claremont school.

He has been a long time instructor of various classes at NIMMA for many years. Starting with a Youth Brown class, he moved onto participating in teaching adults during regular classes. Since receiving his Nidan rank at sixteen, Sensei Isaiah has been a regular teacher of whichever group he works with. He has instructed teen classes, competitive fighting classes, and ran NIMMA’s before and after school program.

Since taking over the Lebanon branch of NIMMA in January of 2017, Sensei Isaiah has worked with individual students and classes in energetic activities.

Over the course of his training, Sensei Isaiah has practiced Karate, Arnis Lanada, Jukado, Judo, and Brazilian Jiu-Jitsu. He uses these experiences to teach a well-rounded and practical style while focusing on fitness and a family friendly atmosphere.

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Renshi Mitchell Kelly

4th Degree

Renshi (Polished Instructor) Mitchell joined the N.I.M.M.A. dojo in 2002 at the age of 7. He was the first of the Kelly family to join Karate classes and as of 2017 he has been training at the N.I.M.M.A. dojo for 15 years. His martial arts journey includes:

  • Competing in tournaments and being apart of the original Competition/Demo Team
  • Participating in numerous demo’s throughout the years including the first 2 Claremont’s Got Talent Shows at the Claremont Opera House
  • Being a Karate Camp Counselor for approximately 4 years since the original camps had began
  • Participated in the Judo/BJJ program at the dojo for approximately 5 ½ years beginning from when the program was first added in the dojo
  • Additionally Mitchell has a year of Wrestling experience from the Newport Tigers Wrestling Team
  • Mitchell also taught the N.I.M.M.A. teenage class for a year but unfortunately couldn’t continue teaching the class because of his job at the time

Mitchell is currently working towards his 5th degree black belt and has recently completed his training for the U.S. Army National Guard of New Hampshire and is a Military Police Officer. He also hopes to teach the military and local police departments some martial arts techniques that he’s learned from his training and plans on working in one of the local police departments in the future.

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Sensei Cassidy Kelly

3rd Degree Black Belt

Sensei Cassidy started her martial arts journey when she was 4 years old at N.I.M.M.A. in 2004. She had wanted to join because her brother Mitchell had started Karate at N.I.M.M.A. and she enjoyed watching and participating in the audience waiting area while his Karate classes were in session. Soon after her joining the dojo her Dad and Mom followed suit in that order. Cassidy competed in tournaments and for a few years was apart of the original Competition/Demo Team with her older brother and her friends. During this time period she participated in the first 2 Claremont’s Got Talent Shows at the Claremont Opera House as well as many other demo’s throughout the years. She also was a camp counselor at the Karate Camps for about 4 years starting from when the first Karate Camps began.

In addition she started taking Judo/BJJ when the program was first added at the N.I.M.M.A. Dojo and ultimately received a yellow belt with 3 stripes from her training. Cassidy has also been passionate about assisting with Sensei Brian Dillon’s Women’s Self Defense Program and has assisted teaching these classes for about 5 years. She has recently taken an interest in yoga and hopes to expand upon her yoga practice and knowledge in the years to come. As of May 2017 she has received her 3rd degree black belt (Sandan) and Sensei title. In addition she has also received her honorary Katana (Samurai Sword) and her colors which are orange and black to represent the tiger.

As of August 2018, Cassidy has been training at the N.I.M.M.A. dojo for 15 years. This year (2018), Cassidy has been making an effort to include the LGBTQ+ community in the Dojo and in Dojo related events. She helped start the first LGBTQ+ self defense class at N.I.M.M.A. with Sensei Brian and she helped lead a Karate demonstration at the first annual Rural Pride in Claremont. She plans on doing so for many years to come and she continually strives to make the Dojo an inclusive space for everyone who wants to train in martial arts. She also helped lead The Dojo Cleanup Project over the summer of 2018 and plans on making this an annual event and is working on various other NIMMA related projects when she has free time. She believes in the notion of giving back to the Dojo and the Instructors that have guided her and hopes that everyone will follow suit.

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Sensei Brendan Donohue - 3rd Degree Black Belt

Sensei Brendan began studying martial arts during his first year of law school, obtaining a yellow belt in Tae Kwon Do. He later returned to Tae Kwan Do in 1998 while in CT. Starting from the ground up he achieved a red belt in about three years. (The school was a mix of Tae Kwon Do and Hapkido, the head instructor’s instructor was Master Hwang). After moving to VT in 2001, he lost his way before enrolling at NIMMA (approximately 2010).

He is most proud of being allowed to be part of the teaching team at NIMMA.

His future plans are to keep going to class, always learning, and studying the practical application of martial arts, what works when and why.

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Sensei Karen Chandler - 2nd Degree Black Belt

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I began studying martial arts in January 2011. At that time my sons were taking part in a Tae Kwon Do Club being run by Bill O’Brien out of Fall Mountain Regional High School. I had always wanted to do martial arts but never had the opportunity. Since working out 4-5 days a week wasn’t at a local gym wasn’t giving me the results I wanted it didn’t take too much persuasion to get me onto the floor. And it wasn’t long before I was hooked!

When Mr. O’Brien ended the program in February 2012, I finally visited NIMMA. With the warm family atmosphere, I immediately felt welcome. My sons and I started training. As I began to get more fit, the workouts started getting easier and I joined the demo team to get more mat time. By January 2013 the cravings became insatiable, I needed to learn more and still needed more time on the mat so I started in the Judo/BJJ program. December 2013, I started teaching children’s classes on Saturdays and helping out at other times if needed.
From the start I have been active in tournaments, enjoying sparring but working empty hand and weapons kata as a matter of discipline. In 2013, I witnessed my first Fusion Fighting matches and was hooked. Through hard work and training with skilled partners, I achieved a Triple Crown (kata, kumite, kobudo) and Women’s Fusion Fighting Champion in the Twin States Martial Arts for the 2014 circuit.

In November 2015 I achieved the rank of Shodan. I continue teaching and assisting with weekly children’s classes and am part of the adult teaching rotation. I assist with the various week-long camps during school breaks and day camps as available. I enjoy helping others on their martial arts paths and sharing in the successes as my students attain higher ranks. (Note: Karen was awarded Nidan in May 2017)
Martial Arts has helped me become more fit at 50+ than I have ever been before. I love taking parts in seminars offered by schools and learning new techniques to bring back and share with my dojo family. I continue to work hard to improve my craft as I now must compete with black belts in the regular tournament events and remain undefeated in Women’s Fusion.

With my Nidan testing and Sensei title right around the corner, I am already looking forward to reaching Sandan and receiving my sword. I hope to continue with BJJ into my 70s and be doing karate at 100!

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Sensei Valarie Heacock
2nd Degree Black Belt

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Sensei Nick Heacock
2nd Degree Black Belt


Sensei Widman - 2nd Degree Black Belt

John Widmann has been practicing martial arts since 1983 when he began studying Kodokan Judo under Rick Olstad.  He currently holds a second degree black belt from the United States Judo Association.  From 1992 to 1997, he was an instructor for the Judo Club at the University of Washington.  In addition to teaching Judo there he studied Karate with the University’s Shotokan Karate Club.  From 1997 to 2003, he studied Brazilian Jiu-Jitsu and Muy Thai at the Yamasaki Academy of Martial Arts in Washington DC. In 2003, he moved to New Hampshire and began Teaching Judo classes.  Today, Upper Valley Judo and the National Institute of Modern Martial Arts Offer Kodokan Judo and Brazilian Jiu-Jitsu classes to adults, and Judo classes to children.


Sensei Brian Dillon
3rd degree Black Belt (Parker Kenpo)
Sandan, Sokken Go Kai Do Ryu
Founder, In Yo No Seishin Program

Owner, ATRT llc

Dr. Dillon has been studying Martial Arts since 9th grade in 1972.  Starting with Judo at the YMCA under Emlyn Williams, with Fencing in high school, and continuing Judo in college he then began his training in American (Parker) Kenpo, and achieved his first degree Black Belt from Master Ed Parker in 1990.  At that time he also began studying Hapkido with Art St. Armand to complement the Kenpo.  Second and third degrees in Kenpo followed in the late 90’s and early 00’s.  To continue to expand his knowledge he began training in Tirada Tirsia (A form of Filipino stick and knife fighting) with Frank Ortega and achieved his instructor’s certificate.  Upon moving to Claremont he joined NIMMA and achieved shodan in 2013.  In 2017 he was awarded his 3rd degree rank in Sokken Go Kai Do Ryu. Since then he has been offering a popular Women’s Self Defense program twice a year, and has shared knife and gun training.  Starting in 2015, Sensei Brian has begun the In Yo No Seishin martial arts system.  Intended for adults of any age for whom the rigors and/or requirements of traditional karate preclude their participation.  His students still learn kata, self defense, weapons, and martial arts principles while accommodating injuries or disabilities.  Recently Dr. Dillon has been training in Active Shooter defenses, and is a certified A.L.I.C.E. instructor. Moreover, he has started a company called Active Threat Response Training that offers vulnerability assessment, Men’s & Women’s Self Defense, Active Shooter staff training, and much more.

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Hannah Costa

1st Degree

Sempai Hannah Costa is a shodan (1st degree black belt) and began training at NIMMA 5 years ago in the Mulberry Street Dojo location. She has been on the Competition Team/Team Fusion since 2016 (which she has won two double crowns in sparring and kata as a result) and has competed in two seasons in the circuit. She recently began training in Judo/BJJ, and has been teaching karate classes for 2+ years. She has also participated in a few demos including the 3rd Claremont’s Got Talent Show in 2017 and the 2018 Rural Pride demo that Sensei Cassidy lead. She currently teaches children’s classes on the weekends. She also helps with The Best Camps in Claremont program along with being the front desk receptionist for The Best Before and After School Program.

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Sempai Alessia Trail

Alessia, sometimes known as Lessy, started training with NIMMA as an adult along with her husband and children as a way to get fit and make friends in a new town, they found a welcoming community and were happy to become a part of the NIMMA family.
Sempai Alessia is the primary instructor for the Lil'Dragons classes teaching basic karate along with helping the three to five-year-old children build hand-eye coordination, gross and fine motor skills, confidence and discipline. To her, one of the best parts of teaching is watching a student that has been struggling with a given technique have a 'lightbulb moment' when suddenly it all starts to click into place and they really start to shine.
In addition to teaching, she is an active member of the competition team holding several Twin State champion titles and hopes to pursue more.
She also trains regularly in Judo, Brazilian Jiu-jitsu and has competed in Fusion fighting which is a challenging combination of striking and grappling.
When not at the dojo she spends her days homeschooling her children and enjoys painting, 3d modeling, traveling and spending time in nature. She also has a love of performance art and has dabbled in various circus skills and fire arts.