WE ARE GROWING AGAIN. Full-time and part-time positions available (MUST BE AVAILABLE WEEKENDS). . About the Company. My Gym Children’s Fitness Center is a 600 locations strong international corporation offering the BEST recreational fitness and gymnastics programs and blowout birthday parties for children ages 6 weeks to 10 years of age. If you’ve never heard of My Gym, please visit our website, Instagram, or Facebook (@mygymfun) and get to know ...