Our Team

Chris Marhefka

Chris Marhefka

Owner, Gym Boss

Chris created B3 to have a direct impact on people’s lives, health and fitness. When he was first getting B3 started, he was managing a catering company, working as a bartender, and living out of his car. Now B3 Gym is one of the most prominent fitness communities in Gainesville. He is a CrossFit Level 1, Level 2, and Mobility coach as well as Precision Nutrition Level 1 coach and ACSM-CPT. Chris’s vision is to help one million people improve their health and happiness, and he is well on his way to fulfilling that goal.
Carlee Marhefka

Carlee Marhefka


Carlee started as a member of B3 at its very beginning. She was out of shape and exhausted at 20 years old, and since then has fallen in love with the business and the feeling of getting stronger every day. She is now happy, healthy, and in the best shape of her life. This super fit lady also eats more than most full grown men (all except Jason). As the Co-Owner of B3 as well as a Certified Personal Trainer, she’s here to spread her love of burpees and healthy living with the entire B3 community.
Karen (cropped)

Karen Colwell

General Manager

Karen comes to Gainesville from CrossFit 405 in Oklahoma City, where she worked as the Head Coach and General Manager for several years.

Prior to her time there, she worked at Stanford University logging 1,500 hours of various varsity sports and techniques, including mobility. Karen is an NSCA Certified Strength and Conditioning Specialist, a USA Weightlifting Sports Performance Coach, and has her Cross Fit Level 1 and Level 2 Certification.

Karen got into CrossFit after being a competitive rower for 12 years. After she graduated from the University of Michigan, she continued training with the US National Team. Soon after she stopped rowing, she started competing in CrossFit and Olympic weightlifting competitions and quit her desk job to pursue a coaching career.

Jason Lentz (Bear)

Head Coach/Operations Director

Jason, the strongest man in the gym, started out at B3 as an intern in the summer of 2014. After that, Chris never told him to leave… So he stayed! Jason’s many certifications include CrossFit Level 1, CrossFit Level 2, CrossFit Mobility, and Certified Strength and Conditioning Specialist from the National Sports and Conditioning Association. His nickname “Bear” comes from his brute strength, but he’s also sweet as a teddy bear. Make him do a running WOD, though, and he won’t be too happy.
Sarah Houder

Sarah Houder

Executive Assistant

Sarah wore many career hats before joining B3. She has a bachelor’s in biology from the University of Colorado and a degree in Baking and Pastry from the Art Institute of Washington, DC. She is now our incredible Executive Assistant, taking every task thrown at her and turning out a beautiful, organized product. She is inspired by the community and the drive of our members to improve their lives every day. There is no doubt that Sarah has helped enhance the entire B3 team’s communication and collaboration. And on top of that, she can bake a delicious Paleo cake and has two adorable pets, Motu the dog and Yoyo the cat.

Jonas (“Sweet Baby Jonas”)

CrossFit Coach, Personal Trainer

Gainz Guru Jonas stands behind the amazing community and potential of B3. He’s here to help coach and encourage our members throughout their fitness journeys. He’s been in the Army Reserve for eight years and a CrossFit coach for 4 years. He has CrossFit Level 1 and USA Weightlifting Level 1 certifications. One of Jonas’s strengths is individualization; he loves helping each of our members set goals and achieve them. Jonas also loves getting inked up—he has over fifty tattoos and still counting! His dream goal is to meet President Obama and take him through a series of calisthenics exercises.
Coach Adam

Adam Wood

CrossFit Coach

Coach Adam has always had a passion for fitness and helping others. This passion was born from his extensive athletic background which included playing collegiate football at Tennessee Tech, competing as a Pro Sportbike Freestyle rider for 4 years. He also comes from a Power lifting and endurance training background. He has multiple certifications from the International Sports Science Association (ISSA) including a Certified Fitness Trainer, a Specialist in Fitness Nutrition and a Specialist in Strength and Conditioning. Alongside his ISSA certifications he maintains a couple of CrossFit certifications including his CF-L1 and CrossFit Running. Most recently Adam received his certification as a Pose Method Running Technique Specialist.

Daily Motto: Trust God, live by example, help others, and get a little better each day.

Corey Kessler

Member/Future Coach

Don’t let the beard fool you, Corey is a self-proclaimed “pretty big softy.” He joined B3 as a member, needing something new in his life. Now Corey’s here to get stronger, faster, and help his fellow athletes do the same. He is a certified CrossFit Level 1 coach, and loves to bring knowledge about health and fitness to others.