ACSM stands for American College of Sports Medicine and, as a personal trainer, certification through them is known as the gold standard of certification. It requires more work and it costs more money, but the likelihood of getting a well paying personal training job and being respected when starting a business ist very high if you have one of the three categories of ACSM certifications.
AFAA stands for Aerobics and Fitness Association of America. AFAA personal trainer certification is a fast way to get certification, and the entire certification process can be done completely online.
The National Council on Strength and Fitness (NCSF) is an agency accredited through the National Commission for Certifying Agencies (NCCA). They offer certifications for personal trainers.
National Exercise and Sports Trainers Association (NESTA) has been in operation since 1992. The agency is accredited through the National Commission for Certifying Agencies (NCCA).
The National Personal Training Institute (NPTI) is a program that was created by Eugene Mcllvaine in 1997. NPTI is a comprehensive 500-hour personal training certification program.
NSCA stands for the National Strength and Conditioning Association. This organization has many certifications, but the most popular is the Personal Trainer Certification. This is an entry level certification that can lead holders down the path to a career in the personal training field.