That's why I suggested ACE. It gives a nice overview and it is much more widely recognized than ISSA. Honestly, two different companies (large in the industry) did not recognize ISSA as a national cert. ACE is widely recognized, gives a nice general approach with some detail, and is a great building block. You can always get NASM, ACSM, NSCA, a CSCS or PES, or whatever down the road. NASM and ACSM also have many speciality certs. If you don't have a degree in the field you can get a Sports Fitness Specialist from NASM, they also have integrated flexibility programs, a masters programs, and much more. Check out their webiste.