Your Journey to a Stronger, Healthier You Starts Here!
Achieve lasting results with personalized training and nutrition plans
Meet Rob Callahan
Rob Callahan, owner of Diamond Physiques, is an ISSA Certified Personal Trainer with over 25 years experience in strength training, bodybuilding, body recomposition, and overall fitness. Rob was a collegiate athlete, who suffered a ligament tear in his knee, requiring rehabilitation. During Rehab, Rob regained his passion for working out, as it made him feel better physically, emotionally, and spiritually. Rob knows firsthand what it's like to go through challenging times, including injury, pain, discomfort and time away from the gym. Whatever challenges you're facing with your training, nutrition and supplementation...Rob has the solution!
Benefits Of Services
Rob created Diamond Physiques to assist all types of people in their fitness journey, regardless of age, ability, or background. Rob believes in creating a positive and progressive environment, where all clients feel respected, valued and supported, while generating quantifiable results.
Rob believes everyone has the power to transform their body and mind. Whether you're a beginner, intermediate or advanced lifter, you'll receive the necessary organization and structure with your training and nutrition, to keep you focused and eliminate chaos.
To achieve your fitness goals in strength training, bodybuilding, functional training and body recomposition, you'll need a program customized specifically for you. Rob provides an in-depth consultation and assessment prior to making recommendations. "It’s only by working closely with an individual over the course of several weeks and making necessary adjustments, that a fitness coach can truly help their client be their best".
Rob shows up EVERY day prepared to do whatever it takes to help YOU achieve your fitness goals!
Available Packages as of December 1, 2025:
*General Coaching – 12 or 24 week program – includes In-depth initial assessment, Client-specific training, Individualized meal plans, Supplement recommendations, Weekly check-ins with updates and adjustments as needed.
*One-time assessment, Training and/or Meal plan.
*In-person session rates furnished upon request
Testimonials
“Contrary to the physically imposing stature, Rob is a big teddy bear. Both approachable and knowledgeable; as well as thoughtful and caring, he is always willing to share his insight, experiences and expertise to help guide you a better version of yourself. In short, whatever your training and nutrition goals are, Rob is the guy to help you achieve them.”
Nate C - Scarborough, Maine
Assistant Principal: Cape Elizabeth High School
“Rob’s attentiveness to what my body needs is on point. Everybody is different but with his fine tuning over several weeks he can really pinpoint what I need to be successful.”
Jessica L - Hollis Center, Maine
Scalehouse Operator
“Hey folks, check out Rob Callahan of Diamond Physiques. He is a great guy. I’ve been working with him for 5 weeks and have made significant gains. Rob is knowledgeable, professional, and encouraging. I am so pleased with my progress so far and I can’t wait to see how far I go. Reach out to Rob if you want to make positive changes to your life. Thanks Rob.”
Peggy L - Old Orchard, Maine
"I’ve known Rob Callahan personally and professionally for over 15 years. During that time, I have observed Rob’s commitment to health and fitness and his desire to assist and motivate everyone he comes in contact with.
Rob genuinely cares about your individual health and fitness goals and he has the skillset and experience to make a quantifiable difference in your life!
When you’re ready to take your health and fitness seriously…Call Rob Callahan, an ISSA certified personal trainer, with a strong understanding of bodybuilding, body re-composition, nutrition, supplementation and general wellness."
Bill M – Porland, Maine
Marketing Manager
"I had the pleasure of working with Rob as my nutritionist and found the experience incredibly valuable. He took the time to understand my goals, lifestyle, and health history, and created a personalized plan that was both realistic and effective. Rob is knowledgeable, supportive, and easy to talk to. He makes nutrition approachable and sustainable. I highly recommend him to anyone looking to make meaningful, lasting improvements to their health."
Troy W – South Portland, Maine
Real Estate Agent
"Like many people in their mid 60’s, I was finding myself gaining weight around my waist despite my exercise routine and diet. I thought I was eating healthy foods and was getting enough exercise, however, I was creeping up towards 200 pounds which was not a good goal. I spoke with another gym member who recommended me to Rob Callahan. Through an initial consultation and subsequent diet plan, I soon discovered all the things I thought were good for me were actually hurting me. By committing funds toward this campaign to improve my health and being very honest in my tracking ALL foods by day as well as exercises completed, I started to see results. The one thing I had to learn was that it was completely up to me – my motivation to change my lifestyle and habits made Rob’s program work. His program is not a quick fix, but a lifestyle change over time. My weight before starting with Rob was 195 pounds. Over the course of 24 weeks, I dropped it down to 168 pounds which was a little over 1 pound weight loss per week. My BP went from 128/80 to 111/61. I increased my exercising each day as well. This transformation is far above what my expectations were when I first met with Rob. He is a coach, motivator and mentor to all his clients. I hope that anyone who reads this will consider his program and give it a try."
Online client - Cape Elizabeth, Maine
“Rob is a beast! From a physical standpoint there are not many guys in the gym moving the weight and working out the way he does. The only other place I’ve seen it is in NFL weight rooms and Division 1 weight rooms.
That’s only one piece to the puzzle, though. With Rob, what I’ve been impressed with the most, is his friendliness and willingness to listen. Rob has become a guy I really enjoy seeing when I’m at the gym because of his authenticity and care for people. It is always a breath of fresh air to hang out and talk to Rob.
With Rob, you are getting the best of both worlds!”
Mike McLaughlin - Portland, Maine
Former NFL player and Boston College Football Star
Area Director for Fellowship of Christian Athletes
“I want to give a huge shoutout to Coach Rob, for helping me achieve significant health and fitness improvements through a 12 week training and nutrition program. At 47, I have struggled with weight, high cholesterol, and poor mental health. Despite prior efforts and completing marathons and an Ironman, I couldn't maintain my weight or overcome food addiction alone. With Rob's virtual coaching, I have lost 30 pounds, gained lean muscle, and improved physical capabilities. Having Rob as a professional coach for accountability and support has been so important. I have already signed up for another 12 week program, aiming to become stronger and faster. The program included tailored fitness routines, a daily nutritional plan, weekly feedback, adjustments, coaching, psychological support, direct communication, and encouragement.”
Brian R - Rumford, Maine
Navy Veteran
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