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New Yorkers 1st Choice
Denver's best

HIIT gyms

Made for those who thrive on the high-intensity interval training format and demand a gym that keeps the pace.

Based on 444 Opinions
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Updated May 2026
01
Base6 Fitness image 1
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Fitness center

Fitness center offers scalable HIIT workouts with thoughtful, varied classes that change daily. Atmosphere is welcoming and supportive, fostering a strong sense of community and encouragement among members of all skill levels.

Clean facilities feature a variety of well maintained equipment. Classes focus on HIIT workouts with trainers always prepared and the gym offers a friendly, supportive environment for all levels.

Challenging HIIT classes stand out with a focus on intensity and athleticism. Strength and barbell sessions complement the workouts, creating a well-rounded fitness experience.

People are saying

"You'll feel so comfortable with the friendly community here."

"I loved the individualized support and guidance for proper form in Functional Fitness."

"This gym has a really welcoming and supportive community."

Good to know

1

Base6 Fitness offers a variety of HIIT classes that change daily.

2

All exercises at Base6 are scalable for different fitness levels.

3

The gym has a flexible class schedule to accommodate various routines.

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Traverse Fitness image 1

Gym offers a high-energy atmosphere with a strong sense of community and camaraderie that makes workouts feel like shared victories. Facilities include sauna, cold plunge, and coworking space, creating a human optimization hub beyond typical fitness centers.

Offers an unlike any other atmosphere that goes beyond everyday gym needs. Provides an absolutely incredible experience with a vibe that feels like a new gym home.

Classes include Strength, HIIT, and Altitude options. Workouts challenge endurance and strength, especially the HIIT with Adam sessions.

People are saying

"I found this gym to be the best I had ever been to."

"Chad's HIIT class pushed me to work my hardest."

"I loved the sauna and cold plunge area."

Good to know

1

Traverse Fitness hosts free park workouts for community members.

2

Happy hours are organized regularly to foster social connections among members.

3

Run clubs meet weekly, providing a fun way to stay active together.

03
Duality image 1
Fitness center

Fitness center combines inclusive community with colorful lighting and lively music to create an uplifting atmosphere. Classes offer diverse, challenging workouts supported by encouraging participants. Puppies often appear in the lobby, adding a unique, welcoming touch.

Strong sense of community stands out here. Facilities support a serious fitness journey with a welcoming vibe.

Classes include circuit, HIIT, and ResCon, offering varied challenges. A strong community vibe supports motivation. Workouts mix strength training and cardio for balanced fitness.

People are saying

"This Yoga Spot has a welcoming community and supportive instructors."

"I found this to be the best gym."

"I loved the variety of HIIT and circuit classes offered here."

Good to know

1

Duality offers a wide range of classes that fit various schedules.

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Parking is generally easy, even during peak hours.

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The community hosts fun events like rooftop yoga and trivia night.

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Fit Collective Denver image 1
Fitness center

Fitness center offers a modern, clean space with sunrise views and a supportive, inclusive community. Group classes vary widely, catering to different fitness levels with thoughtful, accessible workouts. The atmosphere feels warm and welcoming, fostering camaraderie and motivation.

A welcoming and motivating environment defines this gym. It offers a space that encourages consistent visits and supports fitness goals effectively.

Classes include a HIIT strength option that is very intense and challenging. Multiple formats like circuit and lifting complement the HIIT offerings.

People are saying

"It's a fun, welcoming environment with a strong community feel."

"The instructors are so energetic and passionate; it's truly inspiring."

"The instructors at this gym are so welcoming and supportive."

Good to know

1

Fit Collective offers a variety of classes including barre, lifting, and yoga.

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Classes are designed to be accessible for all fitness levels.

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Booking classes is easy through their user-friendly app.

05
The Gym Colorado image 1

Powerlifting gym offers 24/7 access with well-equipped spaces and no wait for equipment. Friendly, supportive community creates a welcoming atmosphere without judgment or intimidation. Programming suits all skill levels, blending strength training and HIIT workouts.

Strength training thrives in a clean, organized space with supportive coaches who meet members at every level. The gym fosters a positive community that helps build confidence and personal gains quickly.

Workouts combine strength training with HIIT programming for a solid mix. Sessions are streamlined to integrate both easily every week.

People are saying

"This gym's community makes you feel like you're working out with friends."

"Brandon makes weight lifting feel safe and understandable."

"This HIIT community makes everyone feel welcome and supported."

Good to know

1

The gym is open 24/7 for all your workout needs.

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Expect several social events throughout the year to engage with the community.

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Brandon offers strength classes for extra motivation and guidance.

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The FIIT co. image 1

Gym space includes multiple rooms with top-tier equipment and a circuit setup that lets people work at their own pace. Atmosphere stays inviting and energetic, fueled by fun music and a community focused on hard work and camaraderie. Classes vary from cardio to strength and boxing, offering challenging workouts suitable for all levels.

Multiple rooms support different workouts throughout the day. A strong sense of camaraderie and community fills the space, making it feel welcoming and well organized.

Jeff leads difficult HIIT classes that kick off the day with intensity. Kettlebell sessions fit well alongside the weekly strength and HIIT workouts.

People are saying

"The trainers at this weight lifting gym are great at correcting your form."

"The gym coaches here really care about your form and push you to improve."

"The HIIT instructors are knowledgeable, funny, and supportive."

Good to know

1

The gym offers a variety of classes, including kettlebell workouts and kickboxing.

2

Parking is easy to find near the gym.

3

Classes are designed to be challenging yet can be done at your own pace.

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Fit House Denver image 1
Fitness center

Fitness center combines welcoming atmosphere with supportive community and science-driven programs. Facility includes cold plunge, sauna, and recovery rooms for wellness and injury prevention. Energy stays motivating and non-judgmental, welcoming all ability levels.

Offers lifting only classes, kickboxing, and HIIT alongside recovery options like cold plunge and infrared sauna. The facility is clean and well planned with a layout that supports diverse training needs.

Classes include HIIT, strength training, and kickboxing with well-equipped spaces for all workouts. Infrared saunas and cold plunge add recovery options alongside varied mobility sessions.

People are saying

"This gym's strength training classes are expertly programmed and get you stronger."

"The Cold Plunge community here is so welcoming and inspiring."

"Abbey's HIIT class was masterfully programmed for a great workout."

Good to know

1

Mobility classes are offered every Sunday at Fit House.

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Kickboxing classes are popular and available for enthusiasts.

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The facility includes recovery options like cold plunge and infrared sauna.

08
Endorphin Broadway image 1

Gym offers friendly community and inclusive atmosphere with small class sizes that encourage all skill levels. Energy stays fun and motivating while workouts remain challenging and adaptable to individual needs.

A welcoming and supportive community defines this gym, making workouts feel engaging and inclusive. Facilities are well-maintained and designed to support a variety of fitness routines.

Classes combine cycling, rowing, and body weight exercises for a full-body workout. Sessions include HIIT, Tabata, and boot camp styles with weights and bands to keep intensity high.

People are saying

"This gym has the most welcoming community I've ever known."

"The cycling gym instructors are positive, encouraging, and make classes fun."

"The HIIT classes offer a great mix of exercise styles."

Good to know

1

Endorphin hosts themed classes and events once a month to foster community.

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HIIT classes are available on Thursday evenings, often paired with social activities.

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The gym has a strong sense of community, making it welcoming for newcomers.

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Endorphin City Park image 1

Open workout areas combine with flexible class schedules and 24-hour access to support varied fitness routines. A welcoming community fosters a judgment-free zone where all levels exercise comfortably. Classes range widely from HIIT to yoga, each designed to be challenging yet inclusive.

Classes cover HIIT, Strength, Yoga, Barre, and Boxing with times from early morning to late night. The gym has a positive environment with welcoming athletes and motivating music.

Classes include HIIT, strength training, and boxing with options like spin, barre, yoga, and TRX rowing. Equipment covers everything needed for HIIT and weightlifting, available daily at various times.

People are saying

"The instructors at this gym are super friendly and encouraging."

"The instructors here really know their stuff and bring the hype."

"The HIIT instructors are so friendly and encouraging."

Good to know

1

Free intro classes are available to experience the gym before committing.

2

The gym offers a wide variety of classes, including HIIT, yoga, and boxing.

3

Flexible open gym hours allow for easy access to fit any schedule.

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Denver, Colorado

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