35 five-star reviews 4,000+ hours of coaching ACE Certified Personal Trainer NASM Stretching & Flexibility Coach B.S. Kinesiology, UMass Amherst
Coaching with Jake Kleis

Build muscle, get flexible, and feel great.

Personal training and assisted stretching in Cambridge, MA.

Online coaching wherever you train.

Choose a service Not sure which service fits? Talking with Jake first is free.
Jake Kleis, smiling, in a close-up studio headshot

3 ways to train with Jake

In person · Cambridge, MA

Personal Training

Train one-on-one with Jake at Dirty Water Fitness, a private training studio in Cambridge. He builds your plan, teaches you the lifts, and keeps you progressing week to week.

Best if you want in-person coaching. Beginners and experienced lifters welcome.

New clients start with 5 sessions for $650.
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In person · Cambridge, MA

Assisted Stretching

Jake takes you through a full-body stretch in a private treatment room at Dirty Water Fitness to improve your flexibility, especially in the hips, back, and shoulders.

Best if you feel tight and know you should stretch, but never get around to it. You don’t need to be fit or flexible to start.

First session $65 (half off)
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Online · Anywhere

Online Coaching

Jake builds a new training phase for you every month and reviews your lift videos, with feedback within 24 hours. Train at your own gym or home gym.

Best if you train on your own and want to know exactly what to do to keep progressing.

$997 for your first 3 months, backed by a 14-day money-back guarantee.
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Results from Jake’s clients

Wen before training with Jake in 2022, and after in 2025, visibly leaner and more muscular
Wen O. · In-person client, 2022 → 2025
Anna before training with Jake in 2024, and after in 2026, visibly leaner
Anna K. · In person since May 2025
Personal training

“In my first session I literally laid on the ground after struggling to deadlift a 45 lb bar. Last week I deadlifted 315.”

Tom · 33, desk worker, 4 months in
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Online coaching

“I’ve been the most pain-free [in] the past two months of [working with Jake], most pain-free I’ve been in years.”

Dennis C. · Stuck for five years, trained in his home gym
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Assisted stretching

“Each session, I experienced a noticeable improvement in my flexibility and overall mobility.”

Mary K. · 60s, retired, stretches once a week, plays pickleball and lifts
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Jake mid-rep on a heavy barbell deadlift
Meet Jake

I coach the way I wish someone had coached me.

I fell in love with lifting as a teenager, but I struggled to put what I read into practice. Twelve years of ice hockey left me feeling uneven in how I move, and a nasty low-back injury from doing power cleans made me cautious and led me to overthink my lifts.

I read books, studied the best coaches in the world, and hired coaches of my own. I found positions and cues that helped me feel the intended muscles working, and I built the flexibility each lift needed.

Today, I lift pain-free, I’m stronger than ever, and can do heavy barbell lifts without fear.

Now I coach people to do the same, with a clear plan from day one instead of years of trial and error.

Not sure where to start?

Fill out a short questionnaire about your goals, training history, and schedule. Jake will reach out to talk it through and help you choose the service that fits.

Get started Filling out the questionnaire doesn’t commit you to anything.