Meet our friendly team of



Joe Divosevic - Owner

For Joe - This is A Dream Come True
"Living in the fitness world has been a dream for me since stepping into a gym over thirty years ago. I believe when you have a passion for the fitness field it will show. MAC GYM is not a part time gig, it is my lifestyle."

Bachelor of Science, Sports Management. California University of Pennsylvania

  • SCCC - Strength and Conditioning Coach Certified
  • CSCS - Certified Strength and Conditioning Specialist
  • NASM CPT - Certified Personal Trainer - National Academy of Sports Medicine
  • MASM PES - Performance Enhancement Specialist - National Academy of Sports Medicine
  • 1992 Pennsylvania state powerlifting champion
  • 1992 APF Junior World Records - deadlift and combined lift total
  • Professional Heavyweight Boxer(1995-2010)
  • USA Weightlifting - Level 1
  • USA Boxing Coach
  • CPR, AED, & First Aid, American Red Cross Certified
Here's What I know
"Starting a fitness program is not easy, but it is essential and there are certainly no short cuts. It is the most rewarding journey a human being will ever experience!"

Jane Fontana Divosevic - Owner

For Jane - This is A Place to Gain Wellbeing
"Fitness includes the outside appearance, and the inside health and wellbeing of each MAC GYM client. My vision is for every MAC GYM client is to feel successful, important, and mentally relieved from the stress of life, using nutrition and exercise."


Bachelor of Science, Health and Physical Education K-12. University of Pittsburgh

  • IFPA - International Fitness Professionals Association Certified Advanced Personal Training
  • IFPA - International Fitness Professionals Association Certified Advanced Nutrition
  • SFA - Senior Fitness Association Certified
  • CPR, AED, & First Aid, American Red Cross Certified
Here's What I know
"Believing wholeheartedly in nutrition, I always say nutrition is 90% of training. Without the proper intake of nutrients, any exercise program will not work."

Robert Casamassa

Our youngest boxing instructor, but certainly not a push over. His competitive boxing and martial arts background far exceed his age. Robert ‘s group workouts consist of a balance between authentic boxing techniques, overall conditioning and a dose of mental toughness for all ages!

Ray Snow

  • Professional Kickboxer
  • Undefeated PKA Lightweight World Title Contender - 1980's
  • 5th Degree Shotokan Karate Blackbelt Jiu-Jitsu Muay Thai Instructor
  • Striking and Speed Coach for MMA
  • Multiple Hollywood Film Roles Including Best of the Best, Delta Force II and Universal Soldier

Megan Wollerton

  • Certified Personal Trainer
  • Competitive Amateur Boxer
  • Participates in variety of sports including Gymnastics, Softball, and Swimming.

Megan's positive energy and great attitude make her the perfect fit for our gym. She brings out the best in the men, women, boys and girls whom she coaches. Megan is very passionate about fitness and is a great example for our members.


Christian Kilhof

Train hard, but right is my philosophy. I have been keeping myself in shape my whole life. With my father who was into bodybuilding, some of my earliest memories are of going to the gym with him and learning to stay healthy. And while I started my adult career writing computer code for industrial machinery, the call of the gym and those memories of youth pulled me back towards fitness. So I got my masters and worked in Germany as a personal trainer for 13 years. When I came to the United States, I had to redo my certifications here to comply with US regulations. Now, I have my own small business. My approach and philosophy towards training is safety first because learning the basics instead of diving right into difficult regimens. My clients range from young to senior citizens and everyone in between. As a Certified Personal Trainer and Strength Specialist with a Master of Exercise Science degree, I not only know how to train, but the science behind it as well. My clients are people who want to get in shape. They could be advanced or just coming back to fitness after months or years away from the gym. I used to train people with disabilities, so I’ve always paid attention to proper form and postures before getting people into more strenuous exercise. People need a foundation first if they are going to achieve success and avoid discouragement. While I trained clients in both German and US markets, the differences in the two countries are minor. The commitment levels are the same - if you want to work out, you work out. In Germany, I trained a lot of athletes - hockey players and runners who wanted to improve endurance. Here, there’s a much bigger crowd with varied fitness goals. I train in a gym that Steelers work out in, and everyday people work out in, and they both want to get better. Train Hard Train Smart!

Christian Kilhof
Iron Shark Training Services


Cody Pletz

Coach Cody graduated from Penn State University with a Kinesiology degree focused on exercise science. In conjunction with his degree, he’s learned through internships under premier human performance specialists, Scott Umber of Umberger Performance, as well as Dr. Michael Duffey of Penn State University. He’s worked with many populations, including, delayed motor development youth, multi sport youth athletes, young adults and adults. Coach Cody’s athletic development program aims to improve running technique, speed, agility, coordination, and overall athleticism. Separately, the general fitness programs work on becoming a healthier, more functional person for everyday life. All programs are developed specifically for the individual and their needs in order to achieve effective results for sports and in life.

Yours in good health!
Cody Pletz


Jon Kolb

Jon is a Kinesiology Instructor at Youngstown State University and Penn State University, and he is the Health Science Instructor at Butler Community College. Jon received his Bachelor of Science in Education from Oklahoma State University, attended the University of Pittsburgh for Exercise Physiology, and received his Master of Science in Exercise Science from Slippery Rock University. He holds certifications in Functional Capacity Evaluation and CPR, as well as Medical Graphics Cardiopulmonary Exercise Testing Course from the University of Iowa.

Jon has been the Director of Fitness, Wellness, and Sports Conditioning at Sharon Regional Health System, Defensive Coordinator and Strength and Conditioning Coach and Assistant Professor of Physical Education at Grove City College, as well as Special Projects Coordinator and Vice President of Rehabilitation Services at Nortrim Corporation in Pittsburgh, PA. Jon also spent 13 years as the left tackle for the Pittsburgh Steelers, winning four Super Bowls and, thereafter, spent 10 more years as the Steelers’ Defensive Line Coach and Strength Coach.

In addition to numerous awards and honors, Jon has had several research papers published relating to the benefits of exercise on diabetes and other diseases. Jon and his wife Deborah are residents of Mars, PA and are the proud parents of three sons and 4 grandchildren.

Jon Kolb


Caleb Kolb

Caleb is a graduate of the University of Nebraska where he was a 4-year varsity wrestler and Division I National Qualifier. While at Nebraska, Caleb earned many honors including:

  • Nebraska Student-Athlete Heart & Soul Award (2014)
  • NCAA Championships Qualifier (2013)
  • Tom Osborne Citizenship Team (2014)
  • Nebraska Redshirt of the Year (2009-10)
  • Nebraska Student-Athlete HERO Leadership Award (2013)
  • Nebraska Scholar-Athlete Honor Roll (Spring 2013)
  • Big 12 Commissioner's Honor Roll (Fall 2009, 2010)

Prior to Nebraska, Caleb was an InterMat top 100 recruit and a three-time state qualifier for Grove City High School, where he captured the title his senior year. He posted a 128-22 career record, including a 39-0 mark in 2008-09. Caleb earned All-America honors in 2009 after finishing third at 160 pounds in the National High School Coaches Association Wrestling Championships. He also participated in football as a halfback and outside linebacker, and in track and field as a pole vaulter his first three years of high school. Caleb is currently the Director of Nonprofit Development for Adventures in Training with a Purpose (ATP). He is responsible for creating and implementing fundraising to build a large support base.

Blake Stewart

Blake Leon Stewart

  • ISSA Certified Personal Trainer

I have dabbled in about every sport known to man at some point in my life. Even though football, wrestling, and track were my specialties while competing in youth level athletics I hold a wide range of general sports knowledge. Growing up I was always the “big kid”, a title that I didn’t necessarily welcome especially as I got older. Being 6ft 240 lbs by freshmen year of high school definitely helped on the field but hindered me in all aspects of my life.

I decided enough is enough and started my fitness journey. I heavily educated myself on exercise and nutrition through individual research. After physically and mentally transforming myself I pursued an academic route. I completed my degree in Human Performance / Exercise Science from Edinboro University. I was ready to take my new found knowledge to the world.

Upon returning to the area I’ve ran through all the trials associated with working for a corporate gym. I came to the realization that I needed to base my practice in a genuine, wholehearted facility like MAC GYM.

What does the future hold for Blake you may ask? Well the future is you, I’m here, you're here, enough talk ,let’s get to work!

Blake Leon Stewart

Tom Yankello

Tom Yankello

  • 2014 Beaver County Sports Hall of Fame Inductee
  • President of Stay off the Streets, Inc
  • 2007/2008 Honorable mention to Official Top 5 Trainers in the World list by Doug Fischer, Ring Magazine.
  • Worked 200+ World & Regional Title bouts & many other significant nationally & internationally televised bouts.
  • Click here to learn more about Tom
  • Click here to visit's Tom facebook page

Tom, World Class Boxing Gym's Head Trainer and Talent Evaluator, is widely recognized in the boxing world as one the sport’s elite trainers, developing numerous champions and top contenders from the ground floor to the world championship level.

Current and past fighters that Tom has trained include Roy Jones Jr., Paul Spadafora, Calvin Brock, Brian Minto, Monty Meza-Clay, Kiante Irving, Verquan Kimbrough, Morgan Fitch, Teddy Reid, Rod Salka, Andres Taylor.

“If I were managing a fighter and needed a trainer who could take us all the way, Tommy Yankello would be on my short list. What he does with his talent is very impressive. His passion and enthusiasm for the sport, and his commitment to his fighters, is as good as anybody’s.”
- Joe Tessitore, ESPN Boxing
Blake Stewart

Kiante Irving

  • 2018 National Golden Gloves Champion- 165 lbs.
  • 2018 Pennsylvania Golden Gloves Champion- 165 lbs
  • 2017 Team USA Continental Americas Championship- 178 lbs
  • 2017 National Golden Gloves Bronze Medalist- 178 lbs
  • 2017 Pennsylvania Golden Gloves Champion- 178 lbs
  • 2017 National Western Elite Qualifier Gold Medalist- 178 lbs
  • 2016 USA vs Ireland Dual Champion- 178 lbs
    (Billy Conn Award for Most Outstanding Fighter of the Evening)
  • 2016 USA vs Cuba Champion- 178 lbs
  • 5-Time Western Pennsylvania Golden Gloves Champion
Mike Guffey

Mike Guffey

Isolate – Integrate – Improvise

I believe you have to isolate basic movement patterns creating a pain free, mobile and stable platform for your body to effectively build skill and complexity, whether it is running mechanics, a squat or handstands. Once you have efficient isolated patterns you can start to add and integrate load and complexity through a hierarchy of progressions meant to continually add stress so the body will adapt. The end goal is to be able to improvise. By this I mean to interact fluidly and efficiently with your surroundings, whether it is a running back in a football game, an Olympic lifter doing a clean and jerk or something as simple as bending over and picking up groceries.