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Grinders Fitness
5 ★★★★★ 111 Google reviews · BJJ gym in Northglenn, Colorado
Boxing, kickboxing and jiu-jitsu gym, with a range of classes to suit all ages and skill levels.
Plan your first class
- Free trial or intro class most gyms welcome new members with a free trial or intro class — check their site or give them a call to book your first session
- Beginner-friendly all levels welcome, including total beginners — you don't need to be fit or have any experience to start
- No-gi no-gi grappling classes — training in a rashguard and shorts, with faster scrambles and a natural bridge to MMA
- Today see hours ·
- Website & schedule grindersfitnessgym.com — book classes and see the live schedule
- Phone (720) 749-4779
Hours
| Monday | 11:30 AM–1:30 PM, 4:30–8:30 PM |
| Tuesday | 8:30–10:30 AM, 11:30 AM–1:30 PM, 4:30–8:30 PM |
| Wednesday | 11:30 AM–1:30 PM, 4:30–8:30 PM |
| Thursday | 8:30–10:30 AM, 11:30 AM–1:30 PM, 4:30–8:30 PM |
| Friday | 11:30 AM–1:30 PM, 4:30–7:30 PM |
| Saturday | 8 AM–12 PM |
| Sunday | 8–11 AM |
The classes they run
“The coaches at Grinders are patient and passionate in developing the skills in beginners.”
Other martial arts here
“Whether you’re a newcomer to boxing or MMA veteran, you’ll love it!”
“It’s not your typical “boxing-inspired cardio” spot like Rumble, Title, et al - there are former pro and amateur fighters teaching that will help you level up.”
What members say
“Moreover, the community of members is among the most kind-hearted, welcoming, and FUN individuals I've had the privilege of training alongside.”
“I’ve worked with Shannon since my days at Title Boxing, where I first fell in love with boxing — and she’s still just as motivating and supportive.”
“It’s not your typical “boxing-inspired cardio” spot like Rumble, Title, et al - there are former pro and amateur fighters teaching that will help you level up.”
“They always have energetic music playing, and the facility is clean and diverse in what equipment and room you can use.”
“Whether your focus is on strength training, technical sparring, weight loss, or competitive pursuits, they provide comprehensive support.”
From the reviews
I can honestly say joining this amazing gym 3 year ago was one of the best decisions I ever made. I look forward to walking through the doors and always feel pumped up when I leave. Shannon has given me a sense of accomplishment by pushing me to do my best.
I cannot say enough great things about this place! You want a workout to start your day, Jessica brings the energy and intensity to get you started right! You want a workout that makes it feel like it isn’t a workout? Beating up a bag is the best way to go! Shannon is one heck of a trainer!
If I could award 10 stars, I would! This gym and its exceptional team are precisely what you need, regardless of your skill level or fitness objectives. The coaches here are not only knowledgeable and patient but also incredibly encouraging and engaging.
I started working out here a few months ago and I’m completely hooked! The classes at Grinders are challenging and intense, but also really fun and can be adjusted to fit your fitness level. The knowledge, patience, and encouragement of the instructors is amazing, and the community is friendly and supportive.
New to BJJ? Start at Grinders Fitness
Grinders Fitness comes up as a beginner-friendly gym — noted on their own site. If you've never rolled or set foot on a mat, that's exactly who a good beginners program is for. A few things worth knowing before your first week. First, you don't need to be fit or flexible to start — you get in shape by training, not before it, and coaches scale the intensity to you. Second, you won't be thrown into hard rolling — reputable gyms build fundamentals (positions, escapes, and basic submissions) for weeks, live rolling eases in gradually, and tapping early keeps every roll safe. Third, all levels really are welcome — ask about a dedicated beginners or fundamentals class time so your first session is alongside others who are also starting out, and leave your ego at the door. Most gyms are happy to let you watch or try a class first, so reach out before you commit.
Your first BJJ class at Grinders Fitness
Nervous about walking into a BJJ gym for the first time? Almost everyone is, and good coaches expect beginners to come through the door. Here's what to know. What to expect: a typical first class is a warm-up, then drilling basic positions and escapes with a partner — not hard sparring. Rest whenever you need to; no one will bat an eye. What to wear: athletic wear you can move in (or a gi if you have one); you'll train barefoot on the mats. What to bring: water and a mouthguard if you have one — many gyms lend a loaner gi for a first class, so it's worth asking when you call. As you keep training you'll add your own gi (or a rashguard and shorts for no-gi) and a mouthguard. Live rolling eases in gradually, once your fundamentals are solid. Arrive 10–15 minutes early to sign a waiver and meet the coach. It gets easier fast — most people feel far more at home by their third class.
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