FLAGSHIP LOCATION
CHARLESTOWN

Join our flagship location located at the heart of Sullivan Square in Charlestown! We opened our doors in 2021 and are committed to continuing to provide a space perfect for YOU. See below for membership options and included amenities!

JOIN NOW

Book your tour to see the space!

We recommend new members book a walk-through tour to see all that the space has to offer. During your tour, you will have the option to stay and get in a FREE trial workout on us!

Book Now

CHARLESTOWN MEMBERSHIPS

YEARLY

Join our Yearly membership for the best rate! Our Yearly membership is offered at $75/month.

6 MONTH

Our 6 Month Membership is offered at a discounted rate of $85/per month.

MONTHLY

Enjoy the convenience of a month-to-month membership option for $105/month.

JOIN NOW

INCLUDED AMENITIES

Every Mass Underground, Charlestown membership includes access to all of our cardio equipment, machines, free weights, saunas, ice baths, lockers, and facilities.

Your membership grants you access to our Charlestown location Monday-Sunday, 365 days.

more room, more equipment 👌

@bcstrengthofficial hip thrust set up
@thetibbarguy 45°/nordic curl
@hammerstrengthofficial leg press
@betitanfit half rack
@lifefitnessofficial functional trainer

#charlestown #bostonfitness #massunderground #boston

The Next Episode 📺👀

A huge THANK YOU to the best community we could have ever asked for! Your support at our Charlestown location has been nothing short of amazing, and we’re so excited to announce that Mass Underground is expanding to a new neighborhood- Southie🍀 @massunderground.southie

We couldn’t have done this without all of you, and we can’t wait to bring our energy, community, and passion to another location. Stay tuned for more details and OG member benefits😉

📸 @rileykathleenimages

#MassUnderground #NextChapter #SouthieHereWeCome #BostonFitness #BostonGyms #Charlestown #Southie #SouthBoston

We are PUMPED with our newest addition to the gym. Hot and cold therapy just got a whole lot better! Book a tour at the link in our bio to come see what we’re all about.

#renutherapy #redwoodoutdoors #coldplunge #sauna #contrasttherapy #bostongyms

The sauna can be intimidating if you haven’t started incorporating it into your routine yet, but we got you!

Studies have shown that regular use can 📈 improve cardiovascular health and ⬇️ decrease cortisol levels (stress!!)

Try these beginner tips to get started and sweating 🥵

*Not medical advice- please consult with your doctor to find out if sauna usage is right for you!

#bostonfitness #gym #sauna #saunabenefits #workoutroutine #fitness #fitnessmotivation #workoutmotivation #boston #charlestown

New year, new goals? Kick off 2024 with a free, private tour and take advantage of our same day complimentary workout to see if our space is a good fit for YOU and YOUR goals🤝

#bostonfitness #boston #charlestown #weightlifting #lifting #gym #newyear #newgoals #newyearsresolution #workout #workoutwithus #sauna #icebarrel #coldplunge #gymmotivation #fitness

Celebrating✌️years in Charlestown with more equipment, better workouts, and the best members!

If you haven’t checked us out yet, schedule a tour on our website and get in a workout on us!

Wanting to get back into a routine? Book a tour with us to check out the space and stay for a complimentary workout!

Geared up and ready for summer ☀️💪🏼

#bostongym #gym #gymlifestyle #opengym #charlestown #boston #bostonfit #bostonfitness #outdoorworkout #rogue #rougefitness

Morning routine as of late.. ice, lift, sweat, 🔁

#dayinthelife #gymowner #workout #fitness #icebath #sauna #lift #gymworkout #boston

City of champs, come on down and workout like one! Big shout out to @juisemoney and @acidplaydough for the amazing artwork #fitness #gym #bostonstrong #city

Our mascot Cito really taking the two minute breaks between sets to heart today. But we get it, it’s almost the weekend #gymmotivation #fitness #weightlifting #lifting #fitnessjourney #weekendvibes

seventy something calls for outdoor workouts and breaking in some new equipment 😎

#boston #fitness #lifting #charlestown #gymmotivation

Snow day PR with a good buddy @whuddapcraig

“Going to work and clocking in and out doesn’t just happen at the office”- Mr. Canova

About five years ago when training became paramount to my mental and physical health, I finally knew what my father meant. Having a space where you feel motivated to start or finish your day on your own terms is a powerful thing- and Mass Underground strives to be exactly that. This isn’t my gym, it’s our gym.

#lifting #bostonfitness #weightlifting #mentalhealth #physicalheath #bostonbusiness #boston #charlestown

putting the ass in Mass Underground on the new thruster lite from @bcstrengthofficial 🔥

a monday morning reminder💭⁠
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Strength does not come from winning. Your struggles develop your strengths. When you go through hardships and decide not to surrender, that is strength.⁠
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– Arnold Schwarzenegger

January's about over but don't let it be the end of your resolutions. Hold each other accountable and go get after it 👊⁠
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#fitness #motivation #gymmotivation #resolutions #workout

"Mass Underground has become an extension of my home. As an athlete, they have everything I need for strength power and conditioning. The community is great, it's very calm, and I can take my time and be confident every time I walk through the door- it's been the building block for my day to day physical and mental heath exercises."⁠
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^^we didn't even ask him to say that 👀⁠
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#healthandwellness #fitness #lifting #gymlife #mentalhealth #fitnessjourney

New year, new amenities: 🔥☕️💪🏼

#sauna #fitness #bostoncoffee #slatemilk #coffee #caffinated #coldbrew #bostonbrewco #gymlife

1.1.22: Clocked In.⁠
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#happynewyear #resolutions #newgoals #fitnessgoals

Christmas Bells look a little different this year 🔔⁠
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#happyholidays #christmaseve #merrychristmas #smallbusiness #fitness #lifting #gyminspo #kettlebells

heading into the weekend with a whole new perspective🙃⁠
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#perspective #fitnessmotivation #training #fit

making mondays count 👊⁠
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#mondaymotivation #weightlifting #lifting #fitness #gym

Mid week motivation brought to you by a Wild Card win⁠ 🙌🏻⁠
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#gosox #fitnessmotivation #workoutwednesday #weightlifting #gyminspo

Mass never looked so good🔥⁠⁠
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🎨⁠ @juisemoney
📸 @jpjacobs22

#boston #gyminspo #art #photography #mass

this all started with a mission to create a space where people feel motivated and encouraged to discover the best possible versions of themselves- both physically and mentally⁠⁠
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#fitness #weightlifting #gym #community #motivation

Not a fan of missing a Monday either? Check out the link in our bio to make an appointment to come see the space and get in your first workout- on the house.⁠
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#workout #fit #gym #gymlife #strong #getfit #weightlifting #fitness

What are they sellin!? Get some gear while it lasts!
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DM For Purchase- Limited Supply Available!
Ogio MU Hat: $25
Champion MU Tee: $30

📸 @jpjacobs22

#gym #fitness #workout #workoutfit #merch #merchdrop

we are live 🏋🏽
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link in bio for membership options and how to book a tour- first workout on the house!

#nowopen #workout #gym #fitness #charlestown #boston #massunderground

underground (and to the right)
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#gym #fitness #smallbusiness #boston #charlestown #newengland #lifting #weightlifting

Imagine the hell that is @ikea directions. Now triple it and add weight 😅
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#gym #fitness #lifting #weightlifting #rogue #workout #massunderground

The workout before the workouts💀
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#fitness #gym #workout #newgym #newbusiness #comingsoon #lifting #businesslaunch #community #commitment #motivation

Went Rogue.
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MASS UNDERGROUND
Charlestown, MA📍
Coming Fall 2021

Designed by: @brandon.gcummings

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CONNECT WITH US

@massunderground.charlestown

FLAGSHIP LOCATION CHARLESTOWN