Martial Arts Coaching for Real People
I help busy adults and parents build strength, skill, and confidence through Boxing, Muay Thai, MMA grappling, and strength training — all from my private gym in Hoddesdon. No crowds. No noise. Just focused, practical training that fits your life.
About Me
I’m Brett Sizeland — a coach, former professional MMA fighter, and dad of twin boys with additional needs. I know what it’s like to juggle work, family, and fitness. That’s why I built a private gym at my home in Hoddesdon — a quiet space where you can train properly without distractions. I’ve spent decades in martial arts: Muay Thai, Boxing, Wrestling, Judo, and Brazilian Jiu-Jitsu, where I hold a brown belt. My goal isn’t to turn you into a fighter — it’s to help you get fitter, stronger, and more confident through learning the same skills that build real discipline and resilience. Each session is adapted to your life and schedule so you can make steady progress without burning out.
My Coaching Philosophy
My approach isn’t about competition or ego. It’s about helping you rediscover your physical confidence, manage stress, and enjoy learning something meaningful. Basics first — strong foundations build lasting progress. Train smart — adapt intensity to your life, not the other way round. Show up — consistency beats talent every time.
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Ways to Work With Me
1-to-1 Coaching
Private sessions focused entirely on you. Learn proper technique, build strength, and see clear progress week to week.
Small Group Training
Train alongside a few others for extra energy and accountability. Perfect for friends, partners, or parents training together.
Hybrid Coaching
Combine in-person sessions with online programming and support. Ideal if you want structure and accountability between sessions.
What Clients Say
Don't take my word for it, see what my clients have to say
Google Reviews
Coaching with Sustainable Strength has had a massively positive impact on my lifestyle when it comes to health and fitness. The weekly processes make the plan easy to follow and most importantly, sustain. The workout plans are enjoyable and tailored to what you are interested in, as well as any goals you have in mind making them accessible to stick to. Brett is a very motivating coach and always approaches things in a non judgemental manner offering a safe space to make positive changes. Highly recommend to all levels and abilities.
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Rachel Lochhead
1 year ago
Booked in a call with Brett and we discussed my goals, life style and what sort of gyms/equipment I had access to. Brett drew up an easy to follow workout plan and macros target that doesn't take much effort to follow. Weekly check ins help hold me accountable and keep me motivated. A few simple changes have made a massive difference and Brett is easily contactable if needed. Highly recommend this service
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Stuart
1 year ago
I've been working with Brett for 11 months online. I originally followed him after I watched a podcast he'd done with Men's Health talking about the use of AI in the fitness space. I signed up with him shortly after. He knows his stuff, with a storied background in fitness and MMA. Really personable bloke, even online. He's been a consistent source of support through some tricky personal spots, making sure I don't go too far off track. As a result, my training has remained consistent, my strength and fitness have shot up, and continue to do so. Can't recommend him enough!
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Dan Murray
1 year ago
I have a basic background in Brazilian Jiu Jitsu but had never done any wrestling or striking. Brett has a wealth of experience in martial arts and coaching. He has a broad range of coaching options for both PT and martial arts training, and he is coaching some very well respected fighters. I found pricing very reasonable for both one to one and as part of a larger class. I was apprehensive as a complete beginner but Brett is very patient and has a very friendly and approachable coaching style. Highly recommended!
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Dave Smith
3 days ago
I have gained so much confidence and knowledge working 1:1 with Brett. I have waited since I was a teenager to try MMA and now a women in my late 30s so happy and proud that I have gained some small insight into it after all of these years of being nervous to try. Brett is the most encouraging trainer and his patience and knowledge is inspiring.
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Gemma Brown
3 days ago
What a trainer! Thank you very much for the time and effort/ guidance given in our training sessions, Look forward to see where we are in 12 months time!
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David W
3 days ago
Ready to Start?
If you’re ready to train in a focused, realistic way that fits around your life — let’s get started.
Got a question?
Drop me a message and I’ll reply as soon as possible — usually within a day.