Serving Lancaster, PA and the surrounding areas


Z Fitness | Personal Training | Lancaster, PA 2 Fitness

Learn more about our professionals

Fielding a team of certified experts, Z Fitness includes owner Zach Musser, as well as trainers Matt Shirk,  Derek Rithchey and  Shasta Erhart. Serving our local community, we stive to provide you with stellar fitness guidance and advice as you work toward a healthier you.

Zach Musser

I started playing sports around the age of 7 and continued ever since. As a high school athlete, I played football, basketball, and AAU basketball.


My senior year of high school I started to really take weight training seriously.

Matt Shirk

Hi! My name is Matt and I am a trainer here at Z Fitness. I have been training here with Zach Musser for about 3 years. I can honestly say during my time here, having Zach as a mentor and teacher I have learned and acquired lots of knowledge and principles that I and every trainer here at Z Fitness uses.


My passions in life are to help change people lives, and what better way to do that then through fitness. I love being a trainer and helping people reach their goals, and seeing that smile of success on their face. I am here to motivate, encourage, inspire, and help you reach whatever goal you dream of.


A little about my own fitness journey; when I started working out I was only 105lbs. I was a skinny little bean. After about 5 years of training I put on about 80 lbs. of muscle and am now a NPC Men’s Physique competitor.


I want to change people lives because I know what it’s like to not like the body you have and to want more. I did it and so can you. So let myself and the Z Fitness family help you chase your fantaZy body!

Z Fitness is locally-owned and operated company that serves Lancaster and the surrounding areas.


Don’t forget – you receive 24/7 access to the gym when you’re a client!

Call now to sign-up or for more information about Z Fitness!


Take advantage of one-on-one-training, group training and even online workout programs from our reliable trainers today! Call now to schedule a consultation.


Meet the Z Fitness Trainers

Prior to then, my training consisted mainly of plyometric and endurance training. While playing basketball in college and majoring in Exercise Science, I continued to grow more interested and passionate about weight training.


Over the years I developed my physique using weight training principles and plyometric training. In the last year, I began competing in National Physique Committee (NPC) contests in the Men’s Physique division, in which I won my first show and was eligible to compete at the national level.


Most recently I began fitness modeling in NYC, which led to a lot of great opportunities shooting with top photographers.


I began pursuing personal training because of the positive changes fitness gave my life, and I wanted others to experience the same great feeling. I want to help individuals reach their goals, so they can see what a positive change fitness can make in their lives.


I help individuals reach their overall health and fitness goals whatever their goals may be. I believe there is never a goal that is too big or too small that we cannot reach together.


My qualifications include:

  • ISSA-certified personal trainer

  • I attended Eastern University, where I studied Exercise Science

  • I train everyone from collegiate athletes, high school sports teams, models, and military personnel

  • I want to help YOU achieve YOUR goals

  • Z Fitness offers one-on-one training, group training, as well as team training

  • I specialize in sports specific training, speed training, bodybuilding, health and fitness, and diet coaching

Customized Workouts

Derek Ritchey

Derek is a fitness enthusiast who enjoys maintaining a healthy and active lifestyle. He knows that frequent exercise can elevate a person’s mood, energy levels, and quality of life. Derek is a Lancaster county native and loves helping those in the community reach their fitness goals. He realizes that each individual will adapt differently to training regimes and therefor is committed to finding a program that works best for you. With flexible work hours, he can work around your busy schedule to ensure your able to find time to better yourself.  Therefore, allow him and others at Z Fitness to help you build your desired physique and increase your body confidence.



  • Bachelor’s Degree in Kinesiology from Pennsylvania State University

  • American Council on Exercise personal training certified

  • American Red Cross CPR and AED certified

Shasta Ehrhart

Fitness came into my life about 8 years ago; however, more so in the past two years.  I made a promise to myself that I would go into my 40s feeling more fit, healthy, and happy.


I have trained with Zach and saw amazing results with myself on the inside and out. I gained a level of confidence I didn't know would be possible. Then I decided to pursue personal training on top of my nurse career, so I could help others on their journeys.


My favorite workouts include HIIT, circuit training, small groups, as well as bodyweight exercises.  You do not need big gym machines to get the body you desire. Your body is a machine, so let's use it to its fullest potentional.  With challenge comes change!

  • NASM certified