Military Fitness Trainers - Master Fitness Trainer (Army, Navy, Air Force), Force Fitness Instructor (Marine Corps) Bodybuilders - NPC, OCB, NFF, IFBB Pilates / Yoga Instructors Olympic Powerlifters HYROX / CrossFit Athletes WHY? Many applicants that possess the following skill sets and professional certifications have gone on to have successful GDBA careers: Collegiate / Professional Athletes (All sports welcome) Certified Personal Trainers - NASM, ACE, ISSA, NCSF, ACSM.