Changing the way people think about fitness!



Changing the way people think about fitness!



Please call us to schedule a tour


At its core, Body By X is in business to help people reach and maintain their fitness goals.  We think everyone and every BODY is unique and therefore everyone’s fitness program should be unique to them and their goals.  All of these great offerings come at a terrific price!  We believe everyone should have access to affordable exercise.  We created Body By X to meet the needs of those in our community who want a smaller, more personal space to work out.  We’re like no other fitness center, and we believe, as all of our members do, that we’re the best in Marin.


Xavier, and his wife Nadia, are the co-founders and partners of Body By X Skill Development & Training Center. Xavier has been a personal trainer, an architect of mind, body and soul for more than twenty years. His vision for Body By X was to create a space where kids and adults could overcome their physical and emotional fears and improve their self-esteem. 
From X...
Having been in the fitness field for almost 30 years, I’ve seen a lot of people come and go. I began my career on the sales side and quickly realized that just selling people memberships was not the way to help them achieve long term success.  I realized that people needed help beyond just signing a contract. It was at that point that I decided to become a personal trainer. Since then I have helped hundreds of people reach their goals and sustain a healthy lifestyle. Growing up with the lack of a good role model inspired me to become a good role model myself. This is why I gain such satisfaction coaching, training and mentoring kids. We’ve included 2 pieces of equipment at the Center, a leg press and an assisted pull-up sized for kids as young as 6 or 7 years-old.
Over the years, I have learned not just to listen but to really hear the needs of people of all ages. It’s this ability that helps me to encourage people to move beyond their perceived limitations. For example, I help women gain the strength to do exercises using their own body weight, including push-ups and pull-ups. It gives me great satisfaction to see the confidence this instills in them.
I opened Body By X with my wife, Nadia, to build a community of like minded people doing like minded things.  I feel that this kind of environment breeds success.  This is an aspect of Body By X that I believe our members truly treasure.
Nadia is a personal trainer and teaches an endurance indoor cycling class and Aerial Fitness!  She also manages the business side of Body By X including marketing and community outreach.  Nadia has worked in advertising, retail management and as a project manager for a software company.  She has a master’s degree in psychology and all of these experiences have prepared her well for gym ownership!
From Nadia…
Who am I?  Who I am today is a very different person than I was 10 or even 5 years ago.  I had never been to a gym before I met my husband and business partner, Xavier Jarrell, in 2006.  In fact, I guess you could say I was gym phobic!  I fancied myself as an outside exercise person, but my kids will tell you I was never really into exercise before X.  He inspired me to lift weights.  I hired him as my personal trainer.  And while I fell in love with him I also fell in love with weight training.  It’s one of the most empowering things I have ever done!  It has given me so much internal strength and confidence.  Enough confidence that this former gym phobic is now training others to help them reach their goals!
It’s the most rewarding work I have ever done and I am proud to have a business that inspires kids and adults to build strength physically and emotionally.
First and foremost, we are Mom and Dad, sharing sports and fitness with our children is one of our favorite things!  Please stop by our fitness center to say hello and learn more about our philosophy. 


Fitness Center Services

Fitness Center Services

Fitness Center Memberships & Classes - Personal Training - bioDensity

Infrared Sauna - Sports Group Training - Power Plate


Memberships @ Body By X Skill Development & Training Center:

A 1- year GOLD membership at Body By X includes:

FREE classes:

  • Aerial Fitness
  • Indoor Cycling
  • TRX
  • Restorative Stretch
  • Small Group Training
  • Pilates Mat class

Use of our:

An introductory session on our bioDensity device to increase the density of your bones, tendons and ligaments.

We have many membership options available.

Not interested in taking classes but prefer to work out on your own and use our state-of-the-art equipment, infrared sauna, Power Plate and more?  We have a membership option for you!

Email us @ info@getfitmarin.com

Not a member yet? Drop in for $20 a class or $25 to use all aspects of our facility and see how we're different from other fitness facilities in Marin County. We promise you'll love it! Be sure to check out our schedule to see when our fitness classes occur. We look forward to seeing you soon.


We have the best personal trainers in Marin County!  

You can view their profiles here. Personal training fees vary depending on the trainer and how many sessions you purchase. 

Personal Training Information

Please feel free to call us with any questions.



The Non-pharmaceutical solution for building bone and joint density.

The bioDensity system safely aids in increasing bone density by stimulating the body’s natural bone generation process.  Based on existing science of bone compression, bioDensity applies optimal biomechanics and increases density in bone, tendons and ligaments.

See the Video Below

The Surgeon General Chapter 9 States that increases in bone mineral density are stimulated by maximum loading of the musculoskeletal system.

Infrared Sauna Marin

Infrared Sauna Use @ Body By X Skill Development & Training Center

Body By X has the largest, commercial, infrared sauna in Southern Marin!

Infrared saunas have been proven to help with arthritis, detoxification, stress reduction, lowered blood pressure, weight loss, pain relief, improved circulation, psoriasis and other skin conditions, fibromyalgia and aging!

Recent research shows that increasing your core temperature for short periods, as is done by using a sauna, may offer dramatic improvements to your athletic performance. It does this using a concept called “hyperthermic conditioning”. It has multiiple positive effects on your body from increased endurance to the growth of new brain cells.

Email us @ info@getfitmarin.com if you have questions regarding our infrared sauna.


If you're considering introducing your son or daughter to training outside of his her sport please consider Body By X Skill Development & Training Center. Our trainers have years of experience successfully developing young athletes not just into better athletes but into young men and women who are stronger physically, mentally, and emotionally. We challenge them to grow on all levels. We teach them to respect themselves and others. We show them that exercise is a metaphor for life and we give them the discipline it takes to improve. We build well rounded student athletes. Our athletes learn to love exercise! Let Body By X help guide your young athlete on their journey.



As the global leader in whole body vibration technology, Power Plate redefines optimal health and wellness equipment for every age and ability.

Power Plates are engineered to apply the science behind the body’s natural response to destabilization. The Power Plate platform uses a consistent, safe and controlled level of vibration that moves in three directions (up and down, front and back, and side to side).

From rejuvenation and anti-aging treatments to rehabilitation and therapeutic massage, Power Plate provides exceptional results.

Whether you want to look better, feel better, or play better, Power Plate is the solution.

It’s not fiction—it’s science. More than 200 research studies conducted on whole body vibration have shown, when used regularly as part of a healthy lifestyle, Power Plate can help provide numerous wellness and fitness benefits, including:

Strength—   Improves muscle tone, builds explosive power and endurance.

Flexibility—   Increases range of motion, coordination, balance and stability.

Circulation—   Improves and increases blood flow to strengthen the cardiovascular system.

Weight Loss—   Reduces body fat and enhances metabolism.

Cellulite Reduction—   Diminishes the appearance of cellulite.

Alleviate Pain—   Promotes faster recovery of damaged muscles and tendons, decreases pain and improves joint function.


Fitness Classes

Fitness Classes

    Indoor Cycling - TRX - Rowing - Restorative Stretch - Aerial Fitness -
Small Group Training - Core Conditioning Circuit

Indoor Cycling

Indoor Cycling in Marin County

Both an aerobic and anaerobic exercise that incorporates muscle confusion, muscular overload, and endurance training, Indoor Cycling is one of the most versatile exercises. Our instructors take participants through intense sprints, mountain climbs and jumps using speed, resistance and cadence as their gauge.  Perceived level of exertion or training zones are also used to guide participants of ALL levels.

While your muscles may get confused and tired, your mind won’t!  In fact, you may encounter the cyclist’s adaptation to a “runner’s high,” caused by endorphins secreted during workouts. To veteran indoor cyclers, endorphins are a highly addictive, legal, and healthy drug, one that improves their work and family lives by reducing stress levels.

Speaking of family lives, Marin County’s Body By X indoor cycling classes are extended to every member of the family that is ready for a vigorous, fun and efficient workout.


TRX - Total Suspension Training

TRX is a full body strength suspension workout that utilizes a person's own body weight. It's beginner friendly, and you determine how hard or how easy you want it to go. TRX targets different parts of your body while also raising your heart rate offering a cardio - strength training connection. Many class times, including evening classes. Check the schedule for details.



Rowing is a historically rich sport that can now be imitated on an erg machine at Marin County's Body By X.  Rowing incorporates finesse, strength, endurance, and overall fitness.  In fact, it’s one of the few non-weight bearing exercises that works all of the major muscle groups, including your quads, biceps, triceps, lats, glutes and abdominal muscles.  And let’s not forget about the cardiovascular benefits.  A stronger heart and stronger muscles. Bet you didn’t know one piece of equipment could do all that!

Restorative Stretch

Restorative stretch can help you: 

  • Strengthen core muscles
  • Improve your alignment and posture
  • Improve your balance & stability
  • Support the body to be free of injury
  • Improve flexibility, range of motion and ease of movement
  • Tone muscle and relieve muscle tension and soreness.

Class is fun, challenging, and supportive to meet each participants needs. 

Restorative Stretch complements any vigorous endurance training and will leave you centered and refreshed!

Aerial Fitness

Join Marin County's Body By X Co-Owner, Nadia Mcclinton and take your fitness off the floor!

Aerial Fitness is a combination of strength training, yoga, pilates and resistance training performed in a suspended fitness environment which is like nothing you have experienced before!  Sculpt your body in the air as you tone muscles and increase flexibility.  It's not Cirque de Soleil so no worries if you are afraid of heights.  You will work core muscles, stretch and relieve stress using a swing suspended just inches off the ground.  Get ready to increase your flexibility and gain strength.  Experience the countless benefits of inversion--hanging upside down in a swing, including better posture and sleep, elevated mood and brain power and better digestionSome research suggests that inversion can make you more beautiful.  When there is more blood flow to the head, facial capillaries and hair follicles receive more oxygen and nutrients.   Acne, cellulite, fluid retention, and varicose veins have also been shown to be reduced by inverting one's body!  

Small Group Training

Body By X's idea of a "boot camp" is a small group-exercise program


This well-rounded program includes a combination of weight training, neuromuscular (balance/coordination), cardiovascular, and flexibility exercises, geared to help you get in optimal shape.

Get the benefit of personalized attention in this small group setting.



Open Mon – Fri
5 am – 9 pm  
Sat, 5 am – 7 pm
Sun, 7 am – 7 pm

Non Member Hours-
Please call for an appointment


Open Mon – Fri
5 am – 9 pm  
Sat, 5 am – 7 pm
Sun, 7 am – 7 pm

Non Member Hours-
Please call for an appointment


Body By X

5768 Paradise Dr.,
Corte Madera, CA 94925
Tel: (415) 945-9778


Mon-Fri, 5am-9 pm
Sat, 5am - 7 pm
Sun, 7am - 7 pm

Non Member Hours -
Please call for an appointment

Name *
Phone *