Fitness Underground

Fitness Underground 24/7 Gym Memberships
Personal Training
Nutrition Coaching
Powerlifting Members only gym (24 Hour Access). Personal Training Available!

To become a member, just visit our website or email us to set up an appointment.

09/16/2026

Summer is almost over and things are starting to look different 🍁🍂. A new season is the perfect time to build strength, find your people, and make time for yourself.
DM us FALL to ask about our New Membership Promos and Personal Training Plans!

09/15/2026

Maribel on her experience with Coach Tristin:

"My experience with Trist has been nothing but incredible. She is so patient. My confidence has changed working with Trist. Honestly, it has been a 360.
When I first came in, I had no idea what I was doing. I always tried going to the gym by myself, but of course, I never knew what exactly I’m doing. I’m just so glad that I took the chance to be like, ‘You know what? I need a trainer. I need somebody to help me.’
And now I go into the gym by myself, know what I’m working on, and how to work on it.
I definitely want to give a big shout-out to Trist. Not only is she an amazing trainer, honestly, she’s become such a good friend."
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A personal trainer brings more than just a workout! You get a plan built around your goals, guidance on proper form, and accountability when motivation takes a day off.
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DM us to get started with personal training at Fitness Underground!

09/10/2026

Stay locked in.

09/08/2026

Yes or no? 🍍🍕

09/01/2026

Learn how to connect with your lats with this great exercise.

08/31/2026

Dealing with sciatica pain? You aren't alone. Give these exercises a try and don't be afraid to reach out for help.

08/27/2026

Be proud of your accomplishments.

08/25/2026

Give this a shot if you've been dealing with knee pain!

08/05/2026

Small plates, big gains.

Address

1410 E Foothill Boulevard Ste JK
Upland, CA
91786

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