Our Staff

Julia Karlstad, M.Ed., NSCA-CSCS, ISSA-SFN

Founder & President, JKFITNESS, LLC

San Antonio Location

I’m Julia Karlstad and I am the President and Founder of JKFITNESS, LLC. I have worked in the fitness industry and specifically the medical wellness community for several years. I hold over fourteen years of experience developing, implementing and directing exercise, education and training programs within medical based programs and facilities. I am extremely passionate about helping people change their lives through fitness. My business, JKFITNESS, LLC, is a specialized personal training and wellness studio. We perform metabolic assessments, provide nutritional programs, outline individualized exercise prescriptions, and lead individualized and small group personal training sessions…all while focusing on a long-term lifestyle approach to complete wellness. I have a Master of Education in Exercise Science as well as a Bachelor of Science in Basic Sciences from the United States Air Force Academy (USAFA). I have authored two books about exercise as it relates to weight loss, “Rx Fitness for Weight Loss: The Medically Sound Solution to Get Fit and Save Your Life” and “Bariatric Fitness for Your New Life”. Additionally, I’ve been published in numerous periodicals and was featured with one of my clients on TLC’s “My 600 Pound Life” reality show. In 2013, I was voted Reader’s Choice “Best Personal Trainer” and in 2012 I was the “Featured Personal Trainer” on the cover of San Antonio Express’ Trends Magazine. I have a knack for motivating and excel in speaking platforms. I’ve been a guest speaker for several events and organizations to include: American College of Surgeons Annual Convention, Texas Association of Bariatric Surgeons Weight Loss Summit, Obesity Help Conference, Obesity Action Coalition’s Your Weight Matters National Annual Convention, Baptist Vascular Update Conference, the American Diabetes Expo, Methodist Health for Life Support Group, the Neurology Institute of San Antonio, the American Cancer Society and the Northern Arizona University Athletic Department. Before owning my own business, I personally developed and directed an exercise physiology program that consisted of two bariatric hospitals and three medically supervised weight loss clinics. I also spent ten years active duty in the United States Air Force and was an intercollegiate NCAA Division I athlete for the women’s basketball team at USAFA. I hold three nationally recognized fitness certifications and constantly pursue venues to further my formal education. I’m CPR/AED certified and I’m an active member of the American College of Sports Medicine, the National Strength and Conditioning Association, the American Diabetic Association and the Obesity Action Coalition.

Javier Villagomez, Certified Personal Trainer

Fitness Director

San Antonio Location

Hi, I’m Javier Villagomez. I have been enthusiastic about fitness and performance since high school. Basketball was my passion, but there was unfortunately no focus on sport-performance at my school. This motivated me to find ways of improving my performance, ultimately leading me to pursuing a career in fitness and health. I have over 10 years of experience in the fitness industry. I hold a Bachelor of Science in Kinesiology and Health from the University of Texas at Austin, with a specialization in strength and conditioning coaching. In addition, I am a Certified Personal Trainer through the American Council on Exercise. While in college, I had the opportunity to work with the UT Men’s Basketball team as an assistant strength and conditioning coach. I hold over 5 years of experience managing fitness facilities, as well as creating, implementing and directing fitness programs. My time in the industry has provided me the opportunity to coach a wide variety of small and large group fitness classes. I’ve also created summer programs for young athletes to enhance their sport-performance and weight-training. My overall goal is to motivate and improve the health and fitness of as many people as I can while educating them along the way.

Leonardo Gonzalez, ISSA Certified Personal Trainer

Health & Fitness Professional

San Antonio Location

Hello, I’m Leonardo Gonzalez. My passion for health and fitness started in high school where I played football and trained in the strength and conditioning programs. Through college, I trained with powerlifting style programs and currently train for and compete in strongman events. I have a Bachelor of Science in Kinesiology from the University of the Incarnate Word. I am an ISSA Certified Personal Trainer as well as an ISSA Specialist in Strength and Conditioning. I have experience working with and educating various age groups such as coaching youth football, assisting in strength and conditioning programs for high school athletes, and have taught conditioning classes for industrial athletes in a manufacturing setting. I also have experience as a PT technician in a Physical Therapy clinic. I enjoy working with and motivating people to help them achieve their goals.

Colene Stovall, Certified Personal Trainer

Health & Fitness Professional

San Antonio Location

I have been in the Health and Wellness Industry for about 30 years and the fitness industry for 16 of those years. As a Certified Personal Trainer, I specialize in Weight Loss, Functional Fitness, and Interval Training. I am also a Certified Mat Pilates Instructor and Senior Fitness Instructor.  

My sincere belief is that true wellness encompasses more than just exercise or just nutrition. It comes from within and from our commitment to better ourselves.  I believe this includes a positive attitude, a solid spiritual grounding and changing oneself perception, in addition to exercise, proper nutrition and natural supplements.  This way, the client will be able to achieve a more complete aspect of wellness and reach their desired goals.

Brittney Stofferahn

Administrative Assistant & Yoga Instructor

San Antonio Location

Hi, my name is Brittney Stofferahn. I have a strong passion for physical and mental health. Since I was young, I’ve loved dancing and moving my body to music. I feel my best when I am working-out and staying active such as yoga, lifting weights, and going on hikes. I was born and raised in Utah where I went to school to become a licensed massage therapist and built my own Deep Tissue Massage practice for almost 10 years. Working as a therapist I started to learn and understand how much our mental health has an impact on our physical health and healing. I decided to dive into yoga and become certified as a yoga instructor and focus on slowing the body down, allowing the mind to take a break and take a deep breath. My husband and I moved to Texas at the beginning of 2023 to have a new beginning. I started working at JKFITNESS shortly after as an Administrative Assistant and yoga instructor. I have stepped away from massage therapy and will continue my passion for mental health and physical healing as a yoga instructor and life coach.

Llorye Flores


San Antonio Location

I received my BS in Recreation Administration from CSU Sacramento and my MBA from the University of Phoenix.  My husband and I moved our family from California to Texas in 2005 in hopes of finding a better life for our children. 

I started working for JKFITNESS in 2012 as the Administrative Assistant/Bookkeeper.  I left after a year and a half to focus on my family.  In 2014 I started Timberwood Bookkeeping and JKFITNESS was my first client. 

Starting my business has allowed me to spend time with my family which is very important to me.   I travel and homeschool my youngest.  During our travels we visit my son who is in the Coast Guard.  My business also allows me to spend a lot of time with my daughter and grandson.

Carolyn Karlstad

Client Outreach Specialist

San Antonio Location

I’m Carolyn Karlstad, I received my Associate Degree in Paralegal Studies from Kaplan University in Boca Raton Florida and continued my studies there working toward a bachelor’s degree also in Paralegal Studies. I have more than 45 years of working experience as a Paralegal in many areas of law, with an emphasis in debt collection and bankruptcy. My husband and I moved from Alabama to Wisconsin in 2004 when we purchased my home farm where I grew up.

I started working for JKFitness in October 2022 as a Client Outreach Specialist.