About O3 Strength

Welcome to o3 strength!

We are focused on helping every type of athlete reach their full potential. O3 Strength was born out of three strong friendships who have trained together since 2012. We wanted to bring a holistic approach to a class environment with an emphasis on individual goals. 

We offer two types of group classes:

1. O3 Strength. Our classes are constantly varied functional movements performed at high intensity. All workouts are based on functional movements, and these movements reflect the best aspects of gymnastics, weightlifting, running, rowing and more. These are the core movements of life. They move the largest loads the longest distances, so they are ideal for maximizing the amount of work done in the shortest time. Intensity is essential for results and is measurable as work divided by time—or power. The more work you do in less time, or the higher the power output, the more intense the effort. By employing a constantly varied approach to training, functional movements and intensity lead to dramatic gains in fitness.

Overall, the aim is to forge a broad, general and inclusive fitness supported by measurable, observable and repeatable results. The program prepares trainees for any physical contingency—not only for the unknown but for the unknowable, too. Our specialty is not specializing. The program is designed for universal scalability, making it the perfect application for any committed individual, regardless of experience. We scale load and intensity; we don’t change the program.

These classes have two types:
RX Version and a Scaled Version. The coaches will modify for each individual where needed to ensure we keep a safe environment across the board. All the programming will build on itself over the week and month.

2. TEEN Strength & Conditioning Classes. Our TEEN S&C Classes our designed by our CSCS Trainers (Certified Strength and Conditioning Specialists) who apply scientific knowledge to improve your overall fitness and athleticism. Whether you participate in a sport or fitness program professionally, recreationally, or if you are a beginner, these classes are built to help you gain, or maintain, a healthy body. These classes focus on:
+ Body weight activities
+ Strengthening core
+ Maintaining balance
+ Injury prevention
+ Conditioning, Agility, & Plyometrics
+ Intensive type workouts
+ Workouts designed to increase aerobic capacity and develop better functional movements

Whether you are a beginner, intermediate, or advanced athlete, we have a class for you!

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Meet Our team

Jonathan Kronberg

Jonathan Kronberg has coached all over the world for the past decade. He started O3 Sports & O3 Strength because of his love for seeing both youth and adult athletes achieve what they thought was impossible or improbable. Whether its making a team or getting their first pull-up that look on an athletes face is priceless. 

After High School Jonathan joined the United States Coast Guard with the goal of becoming a rescue swimmer. After his enlistment, Jonathan moved back to Ann Arbor, MI and received his Business Degree in Computer Information systems all while starting two different businesses.

+ CF-L1 Trainer (CrossFit Level 1)
+ CrossFit Scaling
+ CWPC (Certified Weightlifting Performance Coach)
+ CSAC (Certified Speed & Agility Coach)
+ USA Basketball Gold Licensed Coach
+ USA Soccer E Licensed Coach

Steve Koski

Steve Koski our Director of O3 Strength and holds a dual Master’s Degree in Sports Nutrition and Sports Performance Training. Steve began his career serving as a medic in The United States Air Force. Following his service he earned a degree from The University of Michigan in Movement Science.  

For the past decade he has worked worldwide as a strength and conditioning coach, personal trainer, and CrossFit coach. 

+ Certified Sports Nutritionist of the ISSN
+ Precision Nutrition Level 1
+ NSCA Strength & Conditioning Specialist
+ IYCA International Speed & Agility Specialist
+ USAW Olympic Lifting Level 1
+ CrossFit Levels 1 & 2
+ CrossFit Mobility
+ CrossFit Football
+ CrossFit Powerlifting
+ CrossFit Gymnastics
+ CrossFit Endurance
+ CrossFit Nutrition

Jim Musial

Jim's enthusiasm for coaching is evident from the moment our members walk in the door, His friendly demeanor and attention to detail helps our athletes maximize their time in the gym. From the moment they walk in the door, he has the day’s warm up, workout and cool down laid out and ready to go. Keeping a constant eye on athletes, Jim always makes sure each athlete is performing movements with a focus on technique first, and scaling/modifying as needed for each person’s abilities.

As a former Division 1 athlete at Eastern Michigan University (Track), Jim has always had a passion for athletics which has developed into a passion for helping others achieve and exceed their fitness goals. Jim loves the community that CrossFit brings together and how the programming helps change peoples’ lives!
When not at the gym, Coach Jim spends his time with family and friends, running 5K races each month (preferably those that have beer at the end!) and finding local venues to see his favorite bands performs (yes he’s a closet head-banger).

+ CF-L1 (CrossFit Level 1)

MJ Myles

MJ’s passion for sports & fitness came at a young age. He grew up playing basketball, football and track & field. While still in high school, he coached AAU basketball for his dad’s program, “Triple Threat.” He comes from an athletic family where 5 of his siblings played/play D1 sports; his dad, step dad and step mom as well! After attending Central Michigan University & Mid Michigan Community College, he decided to focus on a career in the automotive industry, while continuing to work towards his health and wellness goals. 4 years later, he decided his passion for health & fitness was his true calling, with the primary goal of changing peoples lives. He loves training for CrossFit competitions & staying up to date on the CrossFit space.

He is a continuous student and is always working to better himself as an athlete and a coach. Outside of the gym you will usually find him hanging out with all his siblings & parents!

+ USAW Olympic Lifting Level 1
+ CrossFit Levels 1