Online Strength & Physique Coaching

ISSA Certified Coach with 25 + Years of Experience. Customized Strategy. Precision Execution. Real Accountability.

Complimentary Consultation Included

Why Train With Diamond Physiques

25+ Years Coaching Experience
Helping clients build muscle, burn fat, and sustain long-term results.

ISSA Certified Strength & Physique Coach
Evidence-based programming designed for real progress.

Fully Customized Coaching Programs
Training, nutrition, and accountability tailored to your lifestyle.

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!
 

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

 “Before working with Coach Rob, I was struggling with eating enough food to get me through the day. My primary goal was to hit a weight on the scale while simultaneously outperforming myself from the day before. Although I was getting leaner, my progress was beginning to plateau, and I found myself struggling to sustain any meaningful progress regarding my cardio or lifts. With that being the case, my relationship with food began to veer towards eating less to try and squeeze out any more fat loss. Ultimately though, I just found that I was beginning to focus solely on the number on the scale and not on how I viewed my physique, my performance in the gym, or how my cardio felt each day.

 

I set out to find a coach that could help to give me a new perspective while also holding me accountable. I like to believe that I bring a certain level of discipline to the table, but sometimes you just need that outside perspective to help drive progress forward. While seeking out a coach I also found myself in the difficult position of being the sole parent to my daughter as my Wife was being admitted to the hospital for an extended stay due to pregnancy concerns meaning my time was stretched thin and my stress was skyrocketed. I spoke with Coach Rob and felt that his experience and approach would prove more than invaluable, I felt that his experience was exactly what I needed. Coach Rob’s questionnaire gave me the voice I needed to explicitly map out where I was in my current fitness journey, and his transparency about his coaching style was a refreshing return to form for me compared to the other coaches I spoke with while going through the searching process. Additionally, Coach Rob was very quick to understand my current circumstance and was happy to work with me while maintaining a strong desire to help me improve on my fitness goals.

 

Through the 12 weeks of training with Coach Rob I made significant progress. The nutrition plan, albeit straightforward in its approach, was what I needed and helped me to finally have the energy needed to perform. Additionally, it helped me to get back to basics and focus on eating quality foods with quality ingredients. The training program incorporated some of my favorite lifts while also adding in some more challenging movements that pushed me resulting in furthering my progress. Overall, after the 12 weeks, I was able to add muscle, strength, and endurance for my cardio sessions while maintaining my current weight and getting leaner. I will say that I have changed my approach to nutrition since working with Coach Rob. His experience was clearly present from day one and shown through for all 12 weeks.

 

Beyond the coaching and personal training aspects I want to highlight how understanding, personable, and how much of a genuine person Coach Rob is. About mid-way through the program my family and I faced some very difficult personal challenges that we still face to this day. When these issues presented themselves, Coach Rob was there not just a mentor, but as an actual friend who was flexible and patient. Small setbacks presented themselves, but never once did Coach Rob denigrate my progress or accuse me of not being committed. Instead, he took the time to be human and to care for myself and my family in a way that most people in this kind of professional relationship would never choose to do. His compassion and kindness helped me to maintain my progress even if it did stall for a week and he helped to get me back on the tracks once I was ready. Afterwards, I was able to continue and finished out the program as planned.

 

As a coach, mentor, and leader, Coach Rob has highlighted himself as the best of the best. I’ve worked with a list of Coaches over my years, but Coach Rob has certainly earned his position at the top of the list. I couldn’t recommend a better coach, and truly believe that with Coach Rob you can achieve your goals so long as you are trusting, patient, and willing to follow.

 

10/10, absolutely no notes to give! I absolutely recommend Coach Rob, and plan to work with him again in the future!”

Nicholas Moore - Ohio

US Army Soldier, Infantry

"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 – Portland, 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

Current Available Packages
 
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

 

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