Crossfit Nucleus

Crossfit Nucleus A Strength and Conditioning facility using group and personal training to help improve fitness daily! Not just a gym, CF Nucleus is Our Community!
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CrossFit Nucleus is a First-Class facility located in Belleville Illinois. SCHEDULE:

--Monday-Friday--
5:00AM-6:00AM
12:00PM-1:00PM (Tues/Thurs/Friday)
9:00AM-10:00AM
4:00PM-5:00PM
5:30PM-6:30PM

--SATURDAY--
8:00AM-9:00AM - CrossFit Group WOD

--Sunday--
Closed

We have a 9000sqft building designed to improve your health & fitness, or your child’s athleticism. We have CrossFit strength & conditioning classes for adults and teenagers. We also specialize in overall athletic development from ages 9-18+ for all sports: football, volleyball, soccer, softball, basketball and more! Message us for details on how you can get an athletic edge on their field or court!!
- Speed - Power - Strength - Conditioning -

We are dedicated to getting people in the best physical shape imaginable. We utilize all aspects of fitness including: running, jumping, lifting, rowing, gymnastics, and everything else imaginable to change our bodies physically. All of our classes are taught by a professional and are extremely motivating to get more out of yourself then you would get alone. Working out in a group will get you better results(physically and mentally), doing full body functional movements will get you better results, constantly varying the workouts will keep getting you results, and working at a higher intensity will force your body to change (physically and mentally). After 3 months of doing CrossFit with CrossFit Nucleus your life will never be the same!!

We hope you all have a wonderful holiday! 🦃 🍽️
11/24/2025

We hope you all have a wonderful holiday! 🦃 🍽️

We hope everyone has a great Thanksgiving!!
11/20/2025

We hope everyone has a great Thanksgiving!!

11/20/2025

A little Wednesday night fitness.

Wall balls and box jump/step overs.

, , …. It doesn’t matter what you choose for the Wall Ball will always be a GREAT tool to improve your overall Fitness!!
Sneak them in as often as you can.


Thank you Veterans!! We are the home of the free because of you, the brave! ❤️🤍💙
11/11/2025

Thank you Veterans!! We are the home of the free because of you, the brave! ❤️🤍💙

We will never forget. We climbed today for the ones who gave their all. For the ones who didn’t get the chance to return...
09/12/2025

We will never forget.
We climbed today for the ones who gave their all.
For the ones who didn’t get the chance to return home that day.
For the ones who ran towards the tragedy.
For the ones that made their last call home.

We. Will. Never. Forget. 🇺🇸💔

Saturday - 8am PartnerMonday - 8am ONLY (Partner/Hero)Tuesday - Normal HoursHave a happy and safe weekend! 🇺🇸
08/29/2025

Saturday - 8am Partner
Monday - 8am ONLY (Partner/Hero)
Tuesday - Normal Hours
Have a happy and safe weekend! 🇺🇸

Nothing says “fun” like a little throw down for some free shoes!! When posted about the “Acid Athletics” challenge, we ...
07/16/2025

Nothing says “fun” like a little throw down for some free shoes!! When posted about the “Acid Athletics” challenge, we dove right in!!! A lot was left on the floor …. Haha we are ready for the next one!!!!
📸:

Sending a big shout out to for completing 300 miles on the Katy Trail this weekend for the Colleen Nesbit Foundation!! ...
07/13/2025

Sending a big shout out to for completing 300 miles on the Katy Trail this weekend for the Colleen Nesbit Foundation!! We are so proud of you!! 🧡

Address

350 Old Fullerton Road
Swansea, IL
62226

Opening Hours

Monday 5am - 8pm
Tuesday 5am - 8pm
Wednesday 5am - 8pm
Thursday 5am - 8pm
Friday 5am - 8pm
Saturday 8am - 11am

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CrossFit Nucleus is a First-Class facility located at 350 Old Fullerton Road, Swansea, Illinois. SCHEDULE: --Monday-Friday-- 5:00AM-6:00AM (must be reserved) 6:00AM-7:00AM (must be reserved) 9:00AM-10:00AM 12:00PM-1:00PM 4:00PM-5:00PM 5:00PM-6:00PM 6:00PM-7:00PM 7:00PM-8:00PM (Wednesday and Thursday NO 6pm Class, Friday NO 7pm Class) --SATURDAY-- 8:00AM-9:00AM - CrossFit WOD 9:00AM-10:00AM - Midwest Menace Team Training 10:00AM-11:00AM - CrossFit WOD --Sunday-- Closed We have over 5,000 square foot of workout space, locker/shower rooms, inferred Sauna, kids area, plenty of outdoor space to change things up, and much more! We are dedicated to getting people in the best physical shape imaginable. We utilize all aspects of fitness including: running, jumping, lifting, rowing, gymnastics, and everything else imaginable to change our bodies physically. All of our classes are taught by a professional and are extremely motivating to get more out of yourself then you would get alone. Working out in a group will get you better results(physically and mentally), doing full body functional movements will get you better results, constantly varying the workouts will keep getting you results, and working at relative higher intensity will force your body to change (physically and mentally). After 3 months of doing CrossFit with CrossFit Nucleus your life will never be the same!!