About Us

Pillars of Fitness


Cardiovascular Endurance

The ability of the heart and lungs to adjust to and recover from the effects of whole body exercise.


Body Composition

The amount of fat mass compared to amounts of lean muscle mass, bone and organs.



The capacity of each joint to move through a full range of motion.


Muscular Strength

The amount of force a muscle can produce for a maximal 1 rep.


Muscular Endurance

The ability of the muscles to perform continuous submaximal force with out fatiguing, or a sustained contraction for a period of time.

Why Green Door Fitness?

Because we strive to be energy independent and to get outdoors.

We are working on becoming a certified Green Business through the city of Denver, we recycle, reuse, and try to reduce our waste by using cloth towels and our own water bottles. We don’t have paper cups or paper towels.

Our motto is We workout hard at Green Door so you can play outdoors! We will have a calender of events posted at the gym and would love to get your ideas on the calender too!

To us physical fitness is the ability to carryout daily tasks with vigor and alertness, without undue fatigue and with ample energy to enjoy leisure time pursuits and to meet unforeseen emergencies. Put easier we want our workouts at Green Door Fitness to be challenging and harder than anything you have in your daily life. So when life happens you are ready! That creates a sense of ease and enjoyment when you are playing with your family, walking the dog, or when tragedy strikes and you need to run for help. We want you to be prepared for anything, which means being Green Door Fit!

Expertise Trainers'' alt=

Our Expertise

Over-Delivering Personal Service (100%)

Weight Loss (90%)

Cleanliness (99%)

Building Great Relationships (99.9%)

Fun Friendly Environment (98%)

"Matt is one of the finest human beings kindest souls and motivating and creative individuals I have ever met. He has made it his life's journey to study the human body and is an expert on nutrition fitness as well as mind and body spirit. He has a very unique approach and is always a positive and motivating influence on his clients."

~ A. Wilson
  • team member

    Matthew Hammel - Owner / Trainer

    Matt is a native Coloradan who grew up in Denver. His first passion was football but a hamstring injury forced him to pursue other avenues for his love of physical challenges. In 2001 he graduated from Adams State College in Alamosa with a degree in Exercise Physiology. In 2001 he obtained his personal training certificate from ACE and is also a certified massage therapist.

    Besides helping his clients meet their own physical and health goals, Matt loves running, mountain biking, and hiking. He’s climbed all of Colorado’s 58 fourteeners. Always seeking a new challenge, he is currently training to climb the California 14ers and other states highest points.

    Matt loves to share his love of the outdoors with his wife and daughter. He’s currently trying to keep up with his wife on the mountain bike and his daughter in gymnastics. "One thing I’ve learned," he said, “is if you don’t take care of yourself, you can’t take care of others.” Being healthy is wealthy!

    Read their interview +

    Where are you from?: Lakewood Colorado
    What are your fitness certifications?: Ace Certified Personal Trainer/Group Trainer and Nutrition Specialist, Kettlebell Certified, Spartan Certified, TRX RIP and Suspension Trainer Certified
    Where did you go to school?: Adams State College
    What is your favorite sport?: Football
    What is your favorite color?: GREEN
    What is your favorite exercise?: Power Cleans
    What is your hobby outside of exercise?: Family time
    Where is your favorite place you've been?: Todos Santos with Maree and Luna. Listening to the waves crash and playing in a 5 ft pool with them
    What is your specialty?: Working towards total fitness for any age. I find myself in creating the perfect plan for you to follow and succeed in your fitness goals
    What is your spirit animal?: Wolf
    What is your cheat food?: Chocolate! Anything chocolate will do. Especially baked goods with chocolate!
    What is your favorite joke?: What did the 0 say to the 8?..... Nice belt.
    What is your favorite funny memory?: After a wonderful trip to Italy with Maree and Luna I ask Luna, "What was your favorite part of the trip?" She answers back, "Our layover in Miami".
    What is your most embarrassing moment?: Having to give my first speech in speech class and finding out after the class from my friends that I had my pants on backwards!
    What is your proudest moment?: Opening Green Door Fitness with all of my friends and family around to be a part of it and share in it with me.
    What is your dream vacation?: A safari in South Africa with Maree and Luna. We will then go to Seal Island to watch the Great White Sharks feed. WOW! That will be cool!
    What is your fitness goal?: To always be ready for anything. I strive to be close to peak performance always. When an adventure, race or life happen -which they always do- I'm more than ready!
    What is one thing no one knows about you?: I don't like sparkling water at all! Gross!

  • team member

    Chealsea - Trainer

    Chelsea comes from Mobile, Alabama with a degree in Strategic Communication. After a few years working in advertising and social media, she decided to switch paths for a career more in line with her personal values. She received her Personal Training Cert from NASM in 2020 and is currently in the midst of entering graduate school for Clinical Mental Health and Counseling, where she hopes to focus on both helping individuals recover from eating disorders and counseling the obese population. Passionate about health from a whole-person perspective, her goal is to encourage self-efficacy through physical fitness and to help others regulate their life experience through conscious food choices. Her niche in fitness is resistance training and mobility, where she prioritizes connecting to the correct muscles through smooth movement. Chelsea also works for The Center for Nutritional Psychology, a 501(c)(3) non-profit, the goal of which is to make nutrition a component of mental healthcare by the year 2030. Her favorite podcast is Mind Pump. Come train with her!

    team member

    Brett DeBoy - Trainer

    Brett was born and raised in Baltimore, MD. He grew up playing soccer and football, and is currently playing rugby with the Denver Barbarians in hopes of turning professional. Brett studied Exercise Science at the University of South Carolina and graduated in 2018, and obtained an ACE personal training certification shortly after.

    Outside of the gym, Brett is eager to experience all of Colorado's outdoor activities. Skiing, climbing and hiking with his dog are a few of his favorites, and he hopes to pick up mountain biking soon. Much of his time is spent training for the rugby season, and is hoping to step into a coaching role at a local high school in the near future.

    Brett is full of energy and always looking to challenge both himself and members in the gym, while also making workouts more enjoyable to those who might be new or intimidated by more traditional gym settings. Stop in and let Brett help you take the first step to a more healthy lifestyle!

    Read their interview +

    Where are you from?: Baltimore, MD. No it’s not ALL like the Wire.
    What are your fitness certifications?: I am a certified ACE Personal Trainer. I also have an extensive background in sports and recovery.
    Where did you go to school?: THE University of South Carolina! Go Cocks!
    What is your favorite sport?: Rugby by a mile.
    What is your favorite color?: Garnet…or purple?
    What is your favorite exercise?: Definitely back squats. Leg day every day!
    What is your hobby outside of exercise?: I really enjoy cooking, especially baking desserts!
    Where is your favorite place you've been?: Probably La Jolla, California or Lake Murray, South Carolina
    What is your specialty?: My mom says I’m special at everything!
    What is your spirit animal?: My spirit animal is a pufferfish, according to primalastrology.com
    What is your cheat food?: There are so many to choose from, but I would have a hard time turning down a fat cheesesteak
    What is your favorite joke?: ANY AND ALL DAD JOKES ARE MY FAVORITE JOKE.
    What is your favorite funny memory?: I don’t have any. I am serious 24/7.
    What is your most embarrassing moment?: Spilling red wine on the owner of the Pittsburgh Steelers in front of his guests.
    What is your proudest moment?: Spilling red wine on the owner of the Pittsburgh Steelers in front of his guests. Go Ravens.
    What is your dream vacation?: I’m not well traveled, so I would love to explore the Polynesian Islands and live with the locals for a while.
    What is your fitness goal?: My ultimate goal is to represent the USA in rugby in the future.
    What is one thing no one knows about you?: I have 9 years of experience playing the cello, and hope to pick up violin in the future. Also a member of my family wrote the most famous Maryland-themed Christmas song, Crabs for Christmas. Now available on I-Tunes.

  • team member

    Aaron - Trainer

    Aaron is a Colorado native that grew up in littleton. He grew up playing football and lacrosse and pursued football into college. As a football player Aaron weighed 280lbs and when he decided to stop playing he flipped his health around and dropped 80lbs. He received his degree in exercise physiology at fort lewis college and received his CPT through ISSA. Aaron looks to work with youth athletes helping them get to the next level and achieve their goals as well as the general population looking to live a healthier better life. Stop by and let him help you reach your goals.

  • team member

    Will Sasser - Trainer

    Ask Will for his intro when you see him!

    Read their interview +

    Where are you from? I was born in Doylestown, PA. It is around 20 miles outside of Philadelphia.
    What are your training certifications? I am a NASM Certified Personal Trainer, and I am pursuing my NASM Certified Nutrition Coach Certification.
    Where did you go to school? I attended Clemson University. Go Tigers!
    What is your favorite sport? My favorite sport is football. Fly Eagles Fly!
    What is your favorite color? My favorite color is navy blue.
    What is your favorite exercise? My favorite exercise is the deadlift. 
    What is your hobby outside of exercise? My hobbies outside of exercise include traveling, eating great food, and walking my black lab Lulu.
    What is your favorite place you’ve been? My favorite place I have traveled is Brussels, Belgium.
    What is your specialty? My specialty is mixing strength workouts with sport and life specific twists. 
    What is your spirit animal? My spirit animal is my dog Lulu. She is a black lab/pitbull mix.
    What is your cheat food? My favorite cheat food is by far Cookies N’ Cream Ice Cream!
    What is your favorite joke? My favorite joke is “If the early bird gets the worm, I’ll sleep in until there’s pancakes.”
    What is your favorite funny memory? My favorite funny memory is when my friend wore sunscreen on his face at the beach and none of it rubbed in. His face was bright white for the afternoon and he had no idea. He looked crazy and scary at the same time. 
    What is your most embarrassing moment? My most embarrassing moment is when my pants ripped sliding into second in Little League Baseball!
    What is your proudest moment? My proudest moment so far was graduating from Clemson University. 
    What is your dream vacation? My dream vacation is to go back to Ireland with my girlfriend Grace for two weeks!
    What is your fitness goal? My fitness goal is to achieve a lifestyle that balances strength workouts, proper nutrition, and a little fun with all of the discipline
    What is one thing no one knows about you? One thing no one knows about me is that I used to hate olives and now I love them.