Mr. Jill's offers the best Personal Fitness Trainers in the county. All trainers must have a college degree and be certified through the American Council on Exercise. 


Meet Our Personal Fitness Trainers

Roxy Kahler


The need for fitness runs deep in the Kahler lineage, especially if you’re the older daughter of fitness professionals Jill and Robert Kahler. Since growing up around the fitness industry, Roxy developed a passion for fitness, health, and nutrition. Considering Roxy was only 1 year old when her mom opened her first gym, it is safe to say, that the gym became her second home. During her earlier years, she participated and competed in sports such as gymnastics, track and field, and swimming.  Roxy’s passionate sport became competitive high school and club volleyball. She continued her volleyball career into college but has recently decided to pick up cycling again. Beginning at age 2, Roxy rode tandem with her Dad every Saturday morning for 20 to 30 miles. She watched and participated in extensive strength training for improved sport performance and injury prevention plus cardiovascular training that’s needed to be a great athlete. Although, never coming close to her parent’s professional status, Roxy knows what it takes to be an avid athlete and live a healthy lifestyle. She is a firm believer that maintaining a healthy diet and an active lifestyle will significantly improve one’s health and fitness, and also encourage a more positive outlook on life. Graduating from California State University of Fullerton with a Bachelors of Science Degree and obtaining her A.C.E. Personal Trainer Certification, Roxy has now followed in her mother's footsteps by helping others on a daily basis to be the best healthy version of themselves that they can be. She is now the proud manager of Mr. Jill's Body Firm. If you have any questions about the business, she is the person to talk to!

Ian Gordon


Professional Trainer for Mr. Jill’s for over ten years, Ian has had the privilege of training many Orange County teens, young adults, baby boomers and mature adults. He is extremely innovative in his program design. He values education and actively pursues advanced practice courses in order to enhance his already impressive academic achievements.

Ian is a graduate of Chapman University with a Bachelors degree in Movement/Exercise Science with an emphasis in Athletic Training. Ian is certified by the National Strength and Conditioning Association (NSCA) as a certified strength and conditioning specialist. Additionally, he is a certified Resist-A-Ball Core Team Instructor.

As a professional trainer, Ian helps his clients identify and set realistic health and fitness goals based on analysis of their current fitness level and lifestyle factors.

Additionally, Ian identifies clients who are in need of post rehabilitation conditioning and implements an appropriate exercise program for them. He is an expert in correcting eating habits utilizing sound nutritional principles and referring his clients to a qualified dietitian if necessary. Clients interested in improving their golf game, or becoming better runners, cyclists, or high school and/or Club athletes, find Ian a master at sports-specific conditioning.

Livia Peraza


Originally from Venezuela, Livia was equally as passionate about her current profession as she was about obtaining her U.S. citizenship.
Livia found her passion for sport on the tennis court at the age of six. She played tennis competitively throughout high school and college. In order to improve her game, Livia ran and weight trained consistently. This sport schedule gave Livia the intense desire to pursue physical fitness as a career. Although Livia no longer plays tennis, she is now an avid cyclist. Not only does she ride four times per week for a weekly average of more than 150 miles, Livia also maintains her strength training habit of two times per week. Exercise continues to play an very important role in her life.
Livia’s experience as a fitness professional started twenty two years ago in Venezuela teaching aerobics while studying for her Business Administration degree. Upon completion of her degree, Livia became increasingly passionate about coaching others to attain their health and fitness goals; weight loss, cardiovascular fitness, muscular strength, injury prevention, post rehab, and much more. Livia then became certified by the American Council on Exercise as a Personal Trainer and has studied extensively through IDEA Health & Fitness Association and is habitually working on her continuing education credits to maintain her numerous certifications and further her knowledge.
Livia began her career as a Professional trainer for Mr. Jill’s Body Firm in October 2000. She has been a tremendous asset to Mr. Jill’s. Aside from being one of the best Trainers in the industry, Livia is always concerned about her quality of training and the well being of her clientele. She is always well prepared in advance for each and every client session with new and innovative exercises. Even after several years of training, a client never has the same workout! Livia always gives 100%!

In Livia’s words, “It has been such a great experience working at Mr. Jill’s. It feels like family. I am very proud to be a part of the Mr. Jill’s team.”

Daniel Gustin


Daniel Gustin has a Bachelors of Science degree from the University of Arizona with an emphasis in Psychology, Bio Chemistry, and Nutrition Science. In addition, Daniel is a Certified Personal Trainer with American College of Sports Medicine (ACSM) and a Certified EMT-B. 
Daniel's own personal fitness achievements include being a member of the University of Arizona's Club Water Polo Team and the University of Arizona's Club Wrestling Team. He has a wonderful heart working with the special needs. 

Daniel is a fantastic addition to the Mr. Jill's Training Staff.

Kurt Belfils


Exercise has no age limits -- you're never too old to start. This notion applies to personal fitness trainers, as well. After a successful career as a software engineering executive, Kurt retired at age 48. Reflecting on the years of spending far too many hours confined to conference rooms and airplanes, Kurt's first order of business was to improve his personal health and fitness to ensure a long and very active retirement. Along the way, this simple objective evolved into a passion and ultimately an unplanned second career.
So much for retirement, but Kurt says, "Working as a personal fitness trainer at Mr. Jill's has been far more rewarding." 
Kurt's personal commitment, experience, and knowledge (evidenced by certification from all four of the top national fitness organizations) enable him to help each client achieve his/her unique health and fitness goals. When partnered with a well-qualified personal trainer, the journey is both worthwhile and fun.
Kurt holds a Fitness Specialist Certificate from Irvine Valley College, a B.A. from California State University, Long Beach and a M.S. from the University of Southern California. He is a Certified Personal Trainer with the American Council on Exercise (ACE), the American College of Sports Medicine (ACSM), the National Academy of Sports Medicine (NASM), and is Re-certified with Distinction with the National Strength and Conditioning Association (NSCA). Kurt is also a Certified Lifestyle and Weight Management Consultant with ACE, and a Certified Strength and Conditioning Coach (CSCS,*D), Re-certified with Distinction, with the NSCA. Committed to ensuring a safe training environment, Kurt acquired the Heart Saver AED Certificate (Adult and child CPR and Automated External Defibrillator, and Infant CPR) from the American Heart Association, and the Sport Safety Training and Basic First Aid Certificates from the American Red Cross.
He regularly attends national and state conferences, seminars, clinics and workshops to ensure he is able to incorporate the latest fitness research, techniques and products into the training services he provides at Mr. Jill's. What does this mean for Kurt's clients? Ever-changing workouts that are personalized, engaging, challenging, never routine or boring, focused on the client's goals - and most important of all -- fun.

Saul Williams

Saul grew up in Orange County, Ca and has always led an active, healthy lifestyle with fitness being a big part of his life for many years. Growing up, sports were always a big part of his life, playing soccer, football and surfing. He loves to run, mountain bike, hike and being outdoors. In 2010 he decided to turn his passion for health and fitness into a full time career. He studied through the American Council on Exercise to become a Certified Personal Trainer, Saul is also a Certified TRX Suspension Trainer and is recognized as a Professional Trainer through Idea Fit, the worlds leading membership organization of health & fitness professionals. Saul is also trained and has many years of experience in fitness testing including Hydrostatic Body Fat testing, Vo2 Sub Mask testing and RMR testing, working with a wide variety of people from professional athletes to fitness enthusiasts to people overcoming injuries trying to get back into shape. Saul strongly believes in a good "fitness balance" including Strength training, functional training techniques, cardio training and good nutrition. Saul lives in Irvine and enjoys an active, outdoor lifestyle with his wife and two small children (and a baby on the way!) Along with spending quality time with friends and family.

All of out trainers are CPR and AED Certified!

cpr funny.jpg