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.

Jennifer Mulcahy, Administrative Manager

Health & Fitness Professional

San Antonio Location

Hi, I’m Jen Mulcahy. I have exercised in some form or another for most of my life. I have been a personal trainer for the past 7 years after a 20 year career in the chemical industry directing occupational safety and health compliance programs. I earned my Bachelor of Arts degree in chemistry from Bucknell University, and my Master of Science degree in occupational safety and health engineering from the New Jersey Institute of Technology. I am a certified personal trainer from the American Council on Exercise and have my CPR/AED certification from the American Red Cross I believe in taking a long term approach to accomplish a healthy lifestyle. I specialize in keeping active adults strong, flexible, and mobile and have expertise training people with joint problems and long term illnesses. I have administered and supervised wellness training programs for special populations at a medical based fitness facility. I focus on methodical, calculated fitness plans with a little bit fun and humor to yield success.

Danielle, ISSA Certified Personal Trainer

Health & Fitness Professional

San Antonio Location

Hi, my name is Danielle Sidney, I’ve always had a passion for physical fitness and exercise.  My passion for personal training emerged quickly after my spinal fusion in 2013 as it enlightened me to the importance of individualized training. I originally got my bachelors of science degree at the University of Texas at San Antonio with a concentration in Kinesiology.  I originally wanted to become a PE\ teacher for K-12th grade, but ended up following \ my passion of being a personal trainer in 2018 versus entering the field of education. I became certified through NASM and began my personal training journey.  I personally wanted to feel good during any physical activity and minimize my aches and pains.  This drove me to want to help others become more ] active while reducing pain!  For the past 5 years I have helped people gain muscle, lose weight and bounce back from chronic aches and pains.  I love helping others on their own personal fitness journey.  I also hope my story will help motivate others to overcome chronic pain and injury.

Ethan Bayardo

Health & Fitness Professional

San Antonio Location

Hi, my name is Ethan Bayardo. Fitness and exercise have been my passion since a very young age. My dad is my inspiration as to why I enjoy sports and exercise so much; this started at 6 years old when I started playing football and my dad was the head coach. When I wasn’t at practice, most days my dad would train me and push me to be the best version of myself. This motivational work ethic and drive from my father continued through middle school and high school.  He would push me to new levels; I was working out at 4am and doing more than other athletes in an effort to play collegiate or even professional football.  Around my sophomore year of high school, I started to get attention from different colleges across the country. Leading up to my senior year I had suffered a season ending injury, an ACL tear. This tragic injury flipped my life upside down; I was fearful that I wasn’t going to reach my dream to play football at the collegiate level. Optimistically with the support of my parents and physical therapists, I made a full recovery in 8 months. I ended up playing three seasons at St. Ambrose University in Davenport, Iowa. At that time, I realized that I wanted to pursue a career in Physical Therapy. As I progressed in school, I eventually stepped away from football to pursue my career and moved back home to San Antonio, Texas in May of 2023.  At that time, I was very fortunate to land a job at M.D. Annette Zaharoff’s practice “The Non-Surgical Center of Texas” as a physical therapy technician where I worked alongside Physical Therapist, Dr. Julie Barnett.  My time in the world of rehabilitation has taught me how to structure exercise programs to meet the needs of the patients as well as building a patient/client connection to where people enjoy coming to work with you.  As I now join JKFITNESS, I’m excited to use my previous experience to bridge from physical therapy to personal training and long-term wellness. I love to assess clients’ movement patterns, address imbalances, and design personalized programs that focus on injury prevention and performance. My rehab expertise allows for safe progression from recovery to strength training, while integrating corrective exercises and proper biomechanics into fitness routines. This holistic approach helps clients achieving their health and fitness goals.

Michelle Baglio, RD

Dietician & Nutrition Specialist

San Antonio Location

I’m excited to return to JKFITNESS to support the nutrition piece of your wellness program! I’ve had a connection with nutrition and fitness as integral parts of maintaining good health for many years, even before I started the training that would lead me to become a registered dietitian nutritionist (RDN) almost 25 years ago. Since becoming an RDN, I’ve worked in a variety of settings but mostly in counseling people in sustainable nutrition practices to feel your best and prevent and manage chronic diseases like heart disease and diabetes. Although I have moved from the San Antonio area, I called it home for about 10 years. I met Julia when I first moved to the area and we worked together for several years before she opened JKFITNESS. I was happy to be part of the JKFITNESS family for about 7 years ago and am pleased that I can be part of the team once again virtually. There is no other studio in San Antonio that provides a more holistic approach to wellness!.

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

Bookkeeper

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.