About Marcus Wier
With over 15 years in the fitness industry, Marcus Weir is a certified personal trainer, group fitness instructor, and sports & nutritional coach, bringing deep expertise to both beginners and elite athletes alike. For the past nine years, he has worked with triathletes, Division I athletes, and active individuals looking to maximize performance, recovery, and energy.

Marcus has spent the last 11 years specializing in corrective movement, helping clients prevent injury, restore alignment, and move pain-free through functional training, mobility work, and posture correction.

He is also a dedicated herbal wellness specialist, with over eight years of experience helping individuals heal and thrive through natural, plant-based support. His holistic mindset drives everything he does—connecting the physical, nutritional, and emotional elements of true wellness.

As the founder of Customized Phitness in Springfield, PA, Marcus has built more than just a gym—he’s created a wellness destination. From group classes, personal and semi-private training, to a full juice and smoothie bar, detox programs, and individualized care, everything is designed to help clients transform from the inside out. Over the years, Marcus has guided thousands of clients through powerful changes, not only reshaping their bodies but touching lives and souls through purpose-driven, personalized care.