Fitness Trainers | Staff

Katie Thornhill

The owner of Personal Pilates Plus has been in the fitness and wellness industry since 1983 and opened her personal training/fitness business in 1996.  Katie specializes in Pilates, personal fitness training and MAT-muscle activation techniques.  She graduated with a Bachelor of Science in exercise and sports sciences, with a concentration in Wellness Management from CSU in 1991.  She has been a personal trainer for 35 years and is certified through National Strength and Conditioning Association.  She earned an Associate’s Degree as a physical therapist assistant in 1998 and worked at St Anthony Central in acute neuro-trauma.  She received her Pilates certification in 1999 and has been training herself and others ever since.  Katie  and is now currently being certified in the 2nd level as a MAT, muscle activation techniques, specialist.  She is certified in pre-natal/post-partum exercise.  She taught gross anatomy, anatomy, physiology and medical terminolgy at CSU and DTC.  Her passion is facilitating a balance in life with family, education, occupation, emotional, physical, social, and spiritual wellness.  She loves rock climbing, river rafting, camping and all outdoor exercise (indoors, when she can’t be outside)

Heather Lee

Heather Lee has her Bachelor of Science in Kinesiology from the University of Colorado at Boulder in 1993. She obtained her Physical Therapists Assistant degree from Denver Technical College in 1999. Heather received her Pilates certification from the Donna McLean studio and has been using her knowledge in both a rehab setting and here in the studio. She has worked in the physical therapy setting since 1995 in sports medicine and manual therapy settings. Heather continues to work full time as a Physical Therapist Assistant. In her spare time, Heather enjoys the Colorado outdoors and telemark skiing and competes in triathlons.

Marji Marshall

Exceptional instruction from a kind woman with extensive knowledge and experience. Marji is a certified Pilates Master Trainer and Level 3 Yoga Instructor with over 30 years of experience as a certified personal trainer.
“I have transitioned into teaching more paddle boarding, yoga, Pilates, and cycling. As a retired professional athlete (pro beach volleyball), I have learned a great deal about injury rehabilitation and prevention.”

Carrie Davidson

 I recently moved here from California and am so excited to be working at Personal Pilates Plus! I worked as a Women’s Pelvic Health Therapist for the last 10 years. There I fell in love with Pilates and completed my Comprehension Teacher training certification through Basi Pilates International.  I was able to incorporate Pilates with my patients for rehabilitation and teach group equipment and mat classes.  I specialize in pre and post natal care, back-hip and pelvic disfunction, postural alignment and women athletes. I received my 200 hour yoga certification and look forward to teaching that as well! It’s been a crazy year and I look forward to being back in the studio working with all of you and the amazing instructors here at Personal Pilates Plus.


Hannah Button

Originally from New York, Hannah began her movement career as a professional dancer and teacher. She was introduced to Pilates after a hip injury and was immediately drawn to the
improvements it brought to her recovery and her general sense of well-being. Hannah holds a BFA in dance performance from SUNY Purchase College and completed her comprehensive Pilates training through Ellie Herman Pilates in Brooklyn, New York. Her goal is to share knowledge of the human body while catering to each individual and assisting them in discovering a deeper understanding of their own facility.
When Hannah is not teaching Pilates, she is out in the community as a case manager advocating for vulnerable populations. It is
Hannah’s passion to help people determine their needs and goals both physically and mentally. Welcome to Personal Pilates Plus Hannah!

Jenny Jethnani

My name is Jenny. I was first introduced to Pilates in 2016 by my Mom back at home in Indonesia and was instantly hooked. She suffered from scholiosis and I saw how Pilates helped her. I am PMA certified and received my Pilates teacher training from  The Pilates Center in Boulder  in 2018 where I studied with a number of 2nd generation teachers trained by students of Joseph Pilates as well as a lot of wonderful experienced teachers. During  my pregnancy in 2019 I learn about prenatal pilates from my mentor and I would love to help other women to reap the numerous benefits pregnancy pilates has to offer . 

Pilates has not only helped me stay healthy , it has helped me during childbirth and the recovery after childbirth. I truly believe pilates is an exercise for every person at every stage of their lives.


Heidi Kullman
Hi, my name is Heidi. I am a Colorado Native. I live in Arvada with my Husband, and 3 daughters. I have been teaching Yoga for over 12 years with over 300 Hours of Yoga Teacher Training. I have experience teaching Vinyasa, Power, and Gentle Yoga Classes. I have a certification for Mat Pilates and have been consistently teaching mat classes for over 6 years. I teach a multi-level class placing a strong emphasis on form, and proper technique. I keep my classes fresh and fun. I would love to see you in one of my classes at Personal Pilates Plus in Arvada! Heidi will be teaching Thursday mornings (virtual) at 6:45am for the MAT class as well as 1 Saturday a month! Jump on over to our website and sign up!