Personal Trainer

Justin Killeen, M.S.

Early in 2012, I was driving around Amherst, Hadley, and Northampton looking for local gyms that may be hiring. I was a (relatively) experienced trainer, recent UMass graduate, and circumstances led me to stay in the area longer than I originally anticipated.
I came across a small gym called “Energia Studios”, nestled in next to Hillside Pizza on Route 9. To be quite honest, I think it was because I was getting a slice of pizza for lunch that day. I was intrigued by it, but each time I returned (not for pizza!), the lights were out and the door was locked. Finally, frustrated, I left my resume taped to the door.
Several weeks later, I got a call back, interviewed, and was hired as the personal trainer. I began two other jobs as well. Eventually, I decided that none of it seemed right for me. On a whim, I started “Pioneer Valley Fitness”, what was a mobile or on-site personal training business. I began to really grow as a personal trainer, working with dozens of people out of their homes and workplaces, emphasizing functional movement and injury prevention. Concurrently, I trained the other half of my time at Energia, as I began to get to know and truly embrace the clientele. It was the one job I just couldn’t leave.
Finally, the opportunity presented itself for me to become Spin certified.
From there, it seems as if the rest is history! In that time, I’ve completed my Master’s degree, purchased and and worked to re-brand the first studio, while recently opening our second location, “50/50 Fitness/Nutrition”. I can, without a doubt, say that none of it would have been possible without some truly amazing people who have been there to help and support me from day one. This new brand really embodies our shared vision for the future, and I’m extremely excited to be given the opportunity to present it to you.
So, with all that being said, welcome to the community!



Blog Post: Do You Believe in Second Chances?

Justin  Killeen’s Certifications:

  • ASCM Certified Personal Trainer
  • NSCA Certified Strength & Conditioning Specialist
  • TRX Suspension Training
  • Certified Spinning Instructor
  • Functional Movement Screen – Level 2 Certified
  • Exercise is Medicine – Level 1 Certified

Pat Monska

Pat has over 30 years of experience in the fitness industry and currently spends part of her week teaching a variety of classes at in Lenox. She is a group exercise instructor and personal trainer, passionate about teaching anyone and everyone, from those who are just beginning their fitness journey to seasoned athletes. She believes classes should be interesting, fun and challenging. Pat encourages everyone to work to their full potential and to have the confidence to push themselves out of their comfort zone and achieve their fitness goals. She believes cross training plays a very important role in staying healthy and injury free.

Pat has enjoyed participating in several charity rides in the area with her son, and recently completed a 72-mile ride in Northampton. In addition, she has completed several 5k races with her children which benefited local charities, as well.


  •  AFAA Personal Training
  • NETA Group Exercise
  • Certified Spinning®
  • TRX Suspension Training
  • TRX Rip Trainer
  • Kettlebell X
  • Zumba Certified
  • Vipr Personal trainer
  • Athletic and group certified
  • Indoor Row Certified
  • Silver Sneakers Certified

Meet the rest of our team!

Click here to Meet Michael McCarthy!

Emily Mailloux

A native of Western Mass, Emily spent six years in Boston after her graduation from Smith College in 2011 before returning to the beautiful Pioneer Valley. While in Boston, Emily graduated from the American Academy of Personal Training in 2014 and spent three years developing her career as a strength and nutrition coach.

Emily has a wide background of fitness experience and interests and is an advocate of living an active life, both in and outside of the gym. She is a powerlifter, indoor rock climber, Spartan Trifecta medal holder, and has run over a dozen mud/obstacle course races. She also loves kayaking, hiking, camping, eating, and exploring outdoors.

In her nutrition coaching, Emily emphasizes the importance of building small daily habits to achieve your goals and change your life. She has experience with veganism, vegetarianism, Whole 30, Paleo, and IIFYM, and has helped guide dozens of clients to change their body composition through small daily steps. Emily works individually with each client to find a plan that will work best for them. “With nutrition, as with fitness, there is no one-size-fits-all approach. It’s my job to find a nutrition plan that will work best for YOU and you can stick to for long-term results.”

As a graduate of a women’s college, Emily specializes in empowering women through strength training. “I’ve seen firsthand what can happen when women stand together and rise up as one. Women are a force to be reckoned with, and it’s time we start recognizing that strength. I got into this field because I was tired of being the only female in the weight room. I want to inspire women to take back the weight room and find their strength.”

“I want to help people become the best versions of themselves. I want you to wake up every day feeling awesome about yourself. It doesn’t matter what your goals are—to get stronger, lose weight, have more energy, better eating habits, better sleep—what matters is that you feel your best, and I’m here to help you get there. Together we can find a nutrition and exercise program that is individually tailored to your goals and needs so you can achieve long-term, sustainable results.”


  • Certified Functional Strength Coach
  • Precision Nutrition Level 1 Coach
  • AAPT Boston Certified Personal Trainer
  • Training for Warriors Level 1 Instructor
  • First Aid CPR/AED