Our goal is to give every child the ability, confidence and desire to live a physically active life.


Our Values

In addition to motor skill development, we teach children the following life skills that will allow them to be great teammates and people:

  • Be respectful. It is important to be open minded to others needs and feelings. Show respect to others, yourself and the equipment.
  • Work hard. Be a risk taker – be brave to try new things. It is important to try your best and understand practice is necessary when learning a new skill.
  • Be honest. Be honest with yourself and others.

Our Approach

  • We personalize the learning experience. Our approach allows each child to learn and develop at their own pace through developmentally appropriate learning progressions, which lead to skill competence and confidence.
  • We focus on fundamental motor skill development.  Fundamental motor skills are the building blocks for all specialized movement patterns that make it possible students to participate in a variety of physical activities.
  • We keep students moving. Our activities incorporate significant amounts of aerobic exercise to provide students with immediate health benefits.
  • We make PE fun. Children that enjoy themselves while engaging in physical activity are more likely to continue engaging in an active lifestyle.
  • We have a network of teachers and experts. With GrowFit you're not just hiring a teacher. You're getting access to the collective knowledge of our team of instructors and fitness experts.
  • We provide a supportive learning environment. Children learn best when they’re in a non-competitive environment based on self-improvement and mastery.

Our Team

Joe Callinan
Co-Founder, CEO

Prior to GrowFit, Joe spent 8 years as a Product Leader for a $4 billion dollar technology company.  During that time he was the Product Leader for two new products: QuickBooks Self-Employed and QuickBooks Financing. Joe earned a BS and MBA from Cal Poly, San Luis Obispo and is a Certified Public Accountant.

Russ Nuffer
Co-Founder, COO

Russ is a nationally certified personal trainer with the American College of Sports Medicine and a certified Double Goal Coach by Positive Coaching Alliance. In addition to founding GrowFit, he's the Director of Fitness for The Fit Kids Foundation, a 501(c)(3) non-profit corporation that brings a free after school fitness program to children in underserved communities. He is also on the advisory committee of Stanford GOALS, a research project aimed to improve health through sports and physical activity. With a lifetime love of sports and the outdoors, he enjoys helping people discover the fun in physical fitness and is passionate about introducing a healthy lifestyle to young children. Russ graduated with a BS in Kinesiology with a concentration in Physical Therapy and minor in Psychology from the Cal Poly, San Luis Obispo.

Kelly Caton
Director of Curriculum

Kelly started her professional career working at a large advertising agency in New York City but eventually realized her passion to give back to future generations through a career in education.  Thereafter, Kelly pursued teaching in, Title 1, inner city public schools in Nashville, TN through the Teach for America program.  Now in her seventh year of teaching, Kelly is excited to be a part of the GrowFit team, working on curriculum development and spending time with her students.  She graduated from Penn State University and received her Masters in Teaching from Lipscomb University.

Clare Barbella
Curriculum Specialist & Teacher

Clare has been instructing youth fitness classes for over eight years. She earned her Bachelors in Science in Health Education from San Francisco State University, where she developed a passion for health and teaching. In college, she volunteered her time as a Health Educator facilitating health workshops for high school teens. Upon graduation, Clare pursued a career as a physical education teacher. Additionally, Clare has taught basketball and multi-sport after school enrichment classes. She also teaches adult kickboxing classes in her spare time. She continues her professional development through the International Baccalaureate program and has recently finished her Level 1 certification.


Anthony Sicora

Anthony has 2 years of experience teaching physical education in multiple settings with students ages 5 to 18. Prior to GrowFit, Anthony was in college at the University of St. Thomas. Additionally, he has coached and taught football and track at the high school level. He earned his bachelors of science in exercise science and education from the University of St Thomas, where he studied hard and was involved in many of the exercise clubs around campus. He was inspired to work for GrowFit after he moved to California and saw how fun and exciting the classes looked. He is passionate about football and technology and looks forward to inspiring students to be active.

Bernie Castro

Bernie is new to teaching physical education in settings with students. Prior to GrowFit, Bernie coached basketball at Bayside Stem Academy and St.Peter's School SF. Additionally, he has coached basketball at the middle school level and junior high level and played basketball and football at the high school level. He is passionate about coaching and looks forward to teaching youth sportsmanship and the concept of teamwork.

Bobby Walton

Bobby has taught Physical Education for 6 years in a school setting with students ranging from 5 to 13 years old. Prior to GrowFit, Bobby was an AAU level basketball player and power level volleyball player. Additionally, Bobby has past and present experience coaching power level club volleyball, middle school volleyball and basketball, as well as high school basketball. Bobby is a determined athlete who is passionate about working, coaching, and mentoring youth. He looks forward to an exciting year teaching P.E.

Daniel Mancilla

Daniel has taught Physical Education with GrowFit for 6 years. He has worked with students ranging in age from 18 months to 13 years old. Prior to Growfit Daniel coached pee wee football for 5 years. Additionally Daniel has played rugby at the semi-pro level for 3 years. He is very passionate about making Physical Education fun for everyone. He loves mentoring children and spends his spare time with his daughter.

Desiree Dela Pena

Desiree has 13 years of experience dance education in a variety of styles from hip hop, ballet, jazz to ballroom and social dancing with students ages two to adults. Desiree received a Bachelors of Arts Degree in Dance from San Francisco State University and has been performing in Modern and Hip Hop Dance Companies ever since. Since college, Desiree worked in events and development for several Performing Arts Organizations, such as SF Performances and was the Founding and Artistic Director for Startistic Expressions. Today, she teaches all styles, all over the Bay Area and performs professionally.

Jessica Martinez

Jess is new to the GrowFit team and the physical education world. Prior to GrowFit, Jess was a Supported Employment Coordinator. Additionally, she has coached and taught Swimming at the high school level and swam at the college level. She earned her Masters in Counseling and from Fresno State, where she worked individuals with disabilities for several years. She was inspired to change careers and joined GrowFit after realizing how important physical activity was to health. She is passionate about learning and looks forward to always having fun.

Stanley Sherman

Stanley has taught Physical Education for elementary and middle schools for three years and has been a GrowFit educator for over two years. Prior to GrowFit, Stanley coached multiple middle school basketball teams throughout the Bay Area. Stanley was inspired to work for GrowFit after realizing his true passion in life is to teach and mentor students. He looks forward to another exciting year teaching P.E.



We're hiring

Part-Time Teachers

We’re looking for part-time educators in the Peninsula area that are passionate about teaching; believe in the importance of being physically active and want to have an impact on millions of children. If this sounds like you, join us on our mission to personalize physical education and provide every child with the skills and motivation to live a physically active life.



Teaching PE and enrichment classes

This includes preparation, student assessments and communication with parents, teachers and students. In addition to PE, you may be teaching one or more of the following enrichment classes: basketball, flag football, soccer or PE games.

Furthering the curriculum and lesson plans

We believe the secret sauce to a great PE program is a personalized curriculum that allows each student to learn and develop at his or her own pace. As a teacher, you will be responsible for providing feedback and suggestions on ways to enhance the learning experience.

Improving the customer experience

There is nothing more important than the experience of our students, teachers and parents. All teachers are responsible for ensuring their schools have the best possible GrowFit experience.



  • 2+ years of relevant experience teaching or coaching elementary and middle school aged students
  • Reliable transportation (will require some travel between schools)
  • Teaching credential a plus


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