ACE certified personal trainer

About Justin

Since 2010 I have been safely and effectively helping my clients become the best possible version of themselves by creating personalized training or conditioning routines and easy-to-follow diet guides. I am a former Marine, with his Bachelors of Science with honors, A.C.E. Personal Trainer, A.C.E. Sports Conditioning Specialist, and Body Composition Specialist with over 16 years of training experience. I have competed and placed in 2 W.B.F.F. (World Beauty Fitness and Fashion) Muscle Model Competitions. During our sessions we will incorporate resistance training and conditioning in a fun, practical manner, ending with a cool-down and stretch. My one-of-a-kind training philosophy/routines are based on a combination of volume training with varied rep ranges and weight with hypertrophic training throughout. All the concepts that will be taught by me are built on science, tested in the gym, and backed by my clients results.Whether you want to build muscle, lose fat, get ready for a race, increase athleticism, or just get moving; I will design a personalized and detailed workout routine and diet that I can guarantee will work for YOU!






Areas of Expertise

  • Core and Balance
  • Strength Training
  • Muscular Definition
  • Muscle Gain
  • Sports Performance Training

NCCA Accredited Certifications

ACE Certified Personal Trainer

Additional Certifications

ACE Sports Conditioning Specialist, CPR/AED/First Aid


BS in Graphic Design

Specialty Populations

Bodybuilders, Law Enforcement, LGBTQIA, Men, Military, Models, Student-athletes, Women

2110 El Cajon Blvd

San Diego, CA 92104

No Gym Membership Needed!

It has only been a month and a half but the results have been amazing. I have lost over 3 inches off my waist and down 20 lbs so far. We are on a 20 week program so I can not wait to see what the final results will be.

Noah F.

I have been an active mixed martial art practitioner and instructor for over 8 years. I am also in law enforcement. Training and fitness is life to me. All of that came to a near end when I got hit by a car while I was riding my bicycle training for a competition. The vehicle hit me going 30 mph then fled the scene. In the emergency room the doctor came in and asked if I was a stunt man because my only injuries are lacerations and slight nerve damage to my right arm. The doctor said if it wasn't for my bodily training, I would have been in a very bad state or possibly dead. Before the accident I was meeting with Justin twice a week for weight lifting, strength and conditioning training. I would go home feeling fantastic and looking hard as a rock. After the accident I felt broken hearted and did not know what to do. I could not move my dominant arm without excruciating pain. I felt that my training and career was over. Justin was able to work with me and bring me up to speed in no time. Thanks to his knowledge and skills in the fitness and health industry, I was able to come back in no time and stronger as ever. Thanks to Justin I'm still training and still working. Thank you

Saren P.

I started training with Justin in 2015 when he was still living in Pennsylvania. I truly miss the bond we shared and I absolutely loved is training style and work ethic. I stopped eating sweets, lost a tremendous amount of fat, and continue to keep in contact with Justin to this day. I owe Justin a ton and wish he was still back on the East Coast. Thank you for everything Justin

George P.

I met Justin through a friend of mine who was also a personal trainer here in San Diego. Justin was hosting a sports conditioning class at our local gym and my friend thought I might be interested in trying it out. I was hooked! Justin made the training sessions an enjoyable event that pushed me to my limits each and every time. His training modality and methods of strength training specifically targets the muscle groups I use while power lifting. Rather than just simply "lifting weights" my workouts would also include different types of endurance, static and dynamic strength drills, and stretching. This approach developed my strength and power drastically. If you're looking to learn how to lift correctly, improve your strength, and be conditioned, I would highly recommend Justin and American Training & Performance. Tug J. - NGA Certified Personal Trainer / San Diego, Miami Beach, Bronx

Tug J.

I was a former physique competitor in the 80's and 4 years ago I was hospitalized with a debilitating stomach condition known as fiberticulitus. I had to go through major intestinal surgery and was bed ridden for weeks. I suffered from major muscle loss and decreased range of motion in my core as well as a major strength loss. I decided after my rehabilitation that I wanted to regain my strength, endurance, and overall functional fitness. I have been a client of Justins for over 2 years now and the improvements have been phenomenal. I would HIGHLY recommend him! Joan K. - Security / Prison Guard

Joan K.

Justin Cox was my personal trainer when I lived in San Diego. This guy helped me lose 50lbs in about 5 months, and in that time he helped me gain 10lbs of muscle! Justin is one of the most motivated trainers I have met. He constantly gave me the push that I needed to make it not only to my goal weight but gave me the guidance I needed to continue on! If and when you chose Justin as your trainer, as long as you put in the hard work and never give up, he will never give up on getting you to your goals!!!

Noah Fernandez

I started training with Justin last December and I am completely satisfied with my results. Justin has brought me from a skinny 101 pounder to a fit, tight and added muscle 70 yo woman. His meal plans and hands on training is a perfect combination. I have never felt so good since I’ve been training with him. Thank you Justin Cox, you have made my physical well being something to be very proud of. Respectfully Joan G

Joan G.

Man, I was told to find someone or something to look up to. I find my self looking and watching countless bodybuilding movies, shows or YouTube videos. I took the advice of a body builder he said find one guy that you look up to and follow what he does. I'm glad to say that I look up to you man. It's hard to stay loyal to a diet. Going to the gym is easy. So when I see your results man I just think to my self I will look that good one day.

Shaun S.

I don't mean to sound like a stalker, but this is like my 3rd review on this guy all for the purpose of letting people know the kind of person you'd be dealing with. I've been working with Justin for a long time. Hands down this guy is the best at this. Everything from a meal prep, to a workout plan for you and your spouse, but most importantly getting you to understand what you're doing and why beyond the "losing weight and building muscle aspect" is an extremely meticulous/well thought out process made simple. He doesn't force you to do anything, but rather gets you to want to do better and be better. Being a disabled Veteran I go through my struggles, but I know that I can always count on my boy to get me back on track! Semper Fi!


When I start training with Justin it was pretty rough and he was straight up trying to help me reach my fitness goals, which working on a ranch with horses all day means I. We’re more strength and endurance for my normal work days. Well so far so good! I would totally recommend this dude. He is very dedicated to his clients and he is ridiculously motivated. I had been to 3 different trainers before Justin and by far he is the best one. He provides a safe and fun workout environment.

Aldo C.

I met Justin through a personal training website and I absolutely love working out with him and American Training & Performance. I train with him 3 times a week and I actually look forward to going to the gym now! Justin is always very attentive and involved with all the goings-on in the gym and makes it a point to not only train clients, but teach them while he does it. I am more than satisfied with the way my body looks and how healthy I feel and am so thankful for all of Justin’s help. My gym back home was recently bought by a “Big Box” corporate gym and that only makes me appreciate Justin and the cozy community gym he works at even more. The prices are reasonable and affordable, the people at the gym are friendly, and my trainer, Justin, is unbelievably supportive. I couldn’t imagine working out anywhere else with anyone else! Thank You!

Adam G.

I’ve been training with Justin for the past four months. One of my former employees had originally introduced me to him (and she also still trains with Justin) and I haven’t questioned my decision or her recommendation once. I am very positive that I would have never achieved the current fitness & health level I have at my age, (currently 53) if not for his attention to detail during our sessions. I’ve had a few trainers before, but not like him. He is extremely motivating, a professional, and has a plethora of knowledge about his profession. Very impressive!!! -Thank You Justin

Julie Catano

I genuinely enjoy working out with Justin. He’s knowledgeable, encouraging, patient and above else incredibly personable. He takes his craft seriously and has a professional demeanor and yet is able to make things feel as though you’re hanging out with one of the guys. I always know that I’m going to enjoy our sessions together and I encourage anyone out there who is ready to take their physical traning to the next level to consider him for yourself.

Andrew M.

Justin has been my personal trainer for two years and I have never felt stronger or healthier than I do at this moment. I have achieved this mainly because of Justin with his combo of training methods and his dedication to healthy living. He makes every workout challenging, creative and fun! He has literally changed my life and I will be his client for as long as possible!

Emma G.

I’ve had personal trainers in the past and assumed Justin would be just like them; however, I was mistaken. Justin is far above and beyond the norm. I’ve been training with him for a month and during that time I’ve increased my strength and a perpetually sore shoulder has healed. My aesthetics have improved and people have noticed that I’m looking better than ever. Justin is the real deal and is highly knowledgeable about what works for healing, strength, and aesthetics. As a 51 year old man, I also appreciate that Justin focuses on lighter weights and higher reps. It reduces the chance of injury and is a highly effective training method. In addition, Justin is a marine veteran, a super nice guy, down to earth, and humble. Justin has it all and I am so happy that I found him and have the privilege to train with him.

Ed G.

I’ve been working out for about 2 years seriously. I reached a plateau and I decided to get a trainer, my first experience was awful so I refrained but kept working out but didn’t see the results I wanted because I still don’t understand bodybuilding. Justin came out of nowhere and I can honestly say he saved my confidence and my motivation. He helped me break through that rut I was in. He pushes me harder than anyone I know because he knows I can do it. He’s so personal and constructive that he actually makes killer work outs enjoyable. He’s an amazing dude and I can honestly say you’d be dumb to not want to train with him. His body shows that he knows what he’s doing! He gets a 10 out of 10. Definitely excited to see where I can go and glad he’s there to kick my ass into gear.

Skyler C.

Justin is a phenomenal personal trainer, I highly recommend him to anyone! I'm in my 40s, so I want to tone up and build lean muscle. I'm also extremely concerned about safety - not hurting my back, pulling a muscle, etc. - so during my consultation I told Justin I never ever ever want to do a burpee or anything Crossfit-like. He heard me and designed a program that is fun, challenging and effective. He also mixes things up and progresses me to the next level in a safe timeframe. He's just truly amazing as a person and a professional.

Danielle G.

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