Done-with-you training at a done-for-you standard.

PREMIUM MEDICAL FITNESS

Private, one-on-one medical fitness in Stony Brook & Mount Sinai.

The expertise is ours.

The results are yours.

Our Programs

Private, one-on-one medical fitness, built around your body, your history, and your goals. Assessed, not guessed. Designed around you, not a template.

1-on-1 Training

Private personal training with a credentialed Fitness Specialist, never group, never shared. Every session built from your assessment and tracked in-app.

See training programs

RD-Led Nutrition

Nutrition led by a Registered Dietitian, individualized care built around your health history, labs, and training. From $90/week.

Explore nutrition

Elite Membership

Our most comprehensive experience, daily private sessions, concierge nutrition, unlimited sauna, DEXA benchmark, priority access. By invitation.

Explore Elite

Stretch & Recovery

Private 1-on-1 assisted stretch sessions to improve mobility, reduce tightness, and recover faster between training days.

See stretch sessions

The Medical-Fitness Standard

Assessed, Not Guessed

Redefine is a medical-fitness company, training grounded in evidence, built on assessment, and backed by credentials no commercial gym carries.

State-Backed

NY DOL Apprenticeship

The only gym with a New York State Department of Labor, approved apprenticeship, 2,000+ hours of training our Specialists complete.

Clinical Advisor

Amanda Teeple, NP

A board-certified Nurse Practitioner provides clinical input on our methodology, screening standards, and Specialist education.

Nutrition

Registered Dietitian, Led

The highest nutrition credential there is, individualized medical nutrition therapy within her licensed scope.

Measured

InBody & DEXA

Movement screening, body-composition scans, and reassessments on a set cadence. Every session tracked in-app.

Proven

1,000+ Clients

Private, 1-on-1, never group, a thousand-plus people rebuilt in our two Long Island studios.

Not Sure Where To Start?

Answer 6 quick questions and we'll point you to the program built for your body, your history, and your goals, in about 60 seconds.

Find Your Program →

ADVANCE COMMITMENT

Commit to your program with 12 weeks paid upfront, and unlock an exclusive menu of perks:

PERKS:

REAL PEOPLE. REAL RESULTS. 

See why clients trust Redefine. 

Lynn P.

03:10 29 Jun 26

I have been going to Redefine since January and I can’t say enough good things! I have tried various personal trainers in the past and I have always had problems with them not listening to me as I have some medical concerns and very often would make things worse. The staff at Redefine really focus on you and working within reason to help you strengthen and progress. I have been working primarily with Gigi and she is fantastic but they have different trainers and it is easy to find a fit for what works for you. She knows when to push and adapts the training based on how I might be feeling. I have definitely gotten much stronger and feel a lot better since starting.

Ky H.

23:28 28 Jun 26

gigi is the best trainer ❤️ so kind, smart, and motivating

Jimena P

03:05 23 Jun 26

I had been wanting to try out personal training for a long time, partly to get a momentum going again after a long time away from regular exercise, and partly to learn about weight training and how to build a proper workout, since most of what I'd focused on in the past had been cardio. But as someone in a bigger body, it felt nerve-wracking to find a fitness space that would be welcoming and respectful of my goals, and saw me as more than a potential "before" picture. I've been training at Redefine Fitness for 2 months now and the experience has been sooo awesome! From the beginning, staff were receptive to what I wanted to focus on and get from the experience, and in this short amount of time I have learned so much and am already feeling stronger and having less random body aches. As a really helpful added bonus, they're also flexible in their scheduling and membership pauses, which helps me work it into my crazy schedule. The trainers are all so chill and nice, it really is a great environment, and my trainer Gigi is sooooo wonderfull!!! Great person, attentive teacher, and awesome hype-lady 🙂 Thank you Gigi!!!

Jamie F.

02:16 17 Jun 26

I’ve been training at this gym for over two years, and joining was one of the best decisions I’ve ever made. The trainers are incredibly knowledgeable, genuinely invested in their clients, and create an environment where you feel supported from day one.

A special shout-out to Devon for always sharing his expertise and helping me push myself, and to Meredith for the endless laughs and positive energy she brings every day. The sense of community here is something special, and I’m grateful to be a part of it. Highly recommend!

Makayla P.

18:46 15 Jun 26

Kyle at Redefine Fitness is seriously awesome! Beyond just being super knowledgeable about fitness, his personality really shines through. He's incredibly encouraging and has this knack for making you feel completely comfortable, whether you're just starting out or pushing for new goals. He's always got a positive attitude, a great sense of humor, and genuinely cares about your progress. He'll push you when you need it, but always with a supportive and understanding approach. It's that perfect blend of expertise and a genuinely friendly, motivating personality that makes every session with him so effective and enjoyable. Highly recommend Kyle if you're looking for a fantastic trainer who makes fitness fun and achievable!

megan L.

18:16 15 Jun 26

I’ve had a great experience at this gym. The facility is always clean, the equipment is well-maintained, and the atmosphere is welcoming and motivating. Everyone is friendly, making it a comfortable place to work out regardless of your fitness level.

A special shoutout to Kyle, who has been an incredible personal trainer. He is knowledgeable, patient, and genuinely cares about helping his clients succeed. He takes the time to explain exercises, answer questions, and create workouts that are both challenging and achievable. His positive attitude and encouragement make every session enjoyable, and he always pushes me to do my best while making me feel supported.

I highly recommend this gym, especially if you have the opportunity to work with Kyle!

William O.

16:35 15 Jun 26

I’ve had the privilege of meeting many qualified professionals and incredibly knowledgeable trainers at Redefine Fitness. There wasn’t a single person there who didn’t know how to handle a clients specific needs, or how to help someone who was brand new to the gym, or an experienced lifter reach their fullest potential. Kyle has one of the most methodical and efficient approaches to training I have ever seen and his ability to help others reach their goals in fitness and beyond, transcends the walls of Redefine Fitness. Devon has the most informative and results-based training methodologies I’ve ever heard and seen put into practice with each and every client. They both truly care about their clients results and moreover, their wellbeing and health. I’ve had the pleasure of training with them myself and you can really feel the passion and care they have for Redefine Fitness, as well as their colleagues and clients alike.

If you want to change your life, this is the place to start. Every step of the way is paved out so meticulously for you and the community is so strong you’ll never feel alone.

Brian B.

20:03 01 Sep 25

Had a 2 week experience in Redefine when over from UK. We were given a great welcome and encouragement. Targeted personal training for knee improvement was very professionally delivered - but always with a personal touch and empathy.
Well done Kyle and Hannah! And thanks!

Response from the owner 01:25 02 Sep 25

Thank you for sharing your positive experience, Brian! We're thrilled to hear that our targeted personal training for knee improvement met your expectations and that Kyle and Hannah provided such great support. Your kind words about our team's professionalism and empathy mean a lot to us. We look forward to welcoming you back on your next visit!Thank You

Chris R.

19:37 07 Aug 25

Redefine Fitness in Stony Brook is hands down one of the best gyms I’ve ever been to. The atmosphere is welcoming, the equipment is top-notch, and the whole place is always clean and well-organized.

But what really makes it stand out is the staff. Shoutout to Both Kyle and Kolja. They are incredibly knowledgeable and genuinely care about helping you reach your goals. Whether it's tweaking your form, answering questions, or just offering that extra bit of motivation, they’re always professional and approachable. They know what they're doing, and they make you feel confident and supported.

Response from the owner 19:47 07 Aug 25

Thank you for your wonderful review, Chris! We're thrilled to hear that you had such a positive experience at Redefine Fitness in Stony Brook. Our team, especially Kyle and Kolja, works hard to create a welcoming atmosphere and support our members in achieving their goals. Your feedback about our cleanliness and equipment is greatly appreciated. We look forward to seeing you continue on your fitness journey with us!Thank You

Sarah A.

21:20 23 Jun 25

awesome trainers! everyones great!!

Response from the owner 21:31 23 Jun 25

Thank you for your fantastic feedback, Sarah! We're thrilled to hear that you enjoyed your experience with our trainers. We appreciate your support and hope to see you again soon!Thank You

Lisa B.

13:07 22 Jun 25

I previously posted a positive review for my former Redefine trainer, Amanda. Now that she is in management and I have a new trainer, Hanna, it’s time I sang her praises!

I continue to be proud of myself for making the commitment to working out. This level of exercise and strength training has been the best gift I could ever give myself. I feel strong, sure-footed, and healthy.

I couldn’t do it though without Hanna! She might be young but she’s wise and sensible. We have such a nice rapport that I never hesitate to tell her if I’ve got some little issue troubling me because I know she will find a way to adapt my workouts accordingly. This is wonderful because it means that even if I’m not feeling 100% for some reason, most recently from jet lag, I can still get a good workout in. Most days I feel great and we get to it!

Hanna pushes me, just the right amount. And all the other trainers are so friendly, my little successes are often met with cheers from the entire staff. It’s really sweet, like all of Redefine is cheering for my success!

With this level of support from Hanna and the Redefine family, I know I will be a client for what I hope will be a very long, healthy life!

Response from the owner 20:14 25 Dec 24

Thank you so much for sharing your experience, Lisa! We're thrilled to hear about your journey and the positive impact strength training has had on your life. It's wonderful to know that Amanda and our team have been able to support you in achieving your personal goals. We look forward to continuing this journey with you in 2025 and beyond! Your success is our success!Thank You

V R

14:00 19 Jun 25

Been training here for over 2yrs and it’s been great. The trainers are knowledgeable and polite they’ve helped me work through past injuries. And the new faculty is nice and well equipped.

Response from the owner 14:11 19 Jun 25

Thank you for your fantastic review! We're thrilled to hear that you've had a positive experience over the past two years and that our trainers have been able to support you through your journey. Your progress and satisfaction are our top priorities, and we’re glad you find our new faculty and equipment beneficial. We look forward to continuing to help you reach your goals!Thank You

Why Redefine Exists

Built By Someone Who Needed It First

A college injury left founder Anthony Amen with five herniated discs, a concussion, and chronic migraines. Twenty-five doctors had no answer. Fitness did. He rebuilt himself, and then built Redefine so the next person handed a discharge sheet and no plan doesn't have to do it alone.

That story is the whole reason we assess like medicine, coach like someone who won't give up on you, and track everything to prove you're getting your life back.

Read our story The podcast & blog

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Download our Redefine Fitness app to manage your schedule, book sessions, and more!

TWO PRIVATE STUDIOS.

SAME PREMIUM EXPERIENCE.

PREMIUM MEDICAL FITNESS

Our Programs

1-on-1 Training

RD-Led Nutrition

Elite Membership

Stretch & Recovery

Assessed, Not Guessed

Not Sure Where To Start?

PERKS:

Built By Someone Who Needed It First

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Strength Training for Shoulder Pain and Stiffness: An Evidence-Based Guide

Exercise for Knee and Hip Arthritis: A Strength Training Guide

Strength Training With Lower Back Pain: An Evidence-Based Guide

Strength Training and Blood Sugar: A Guide for Type 2 Diabetes and Prediabetes