First of all, if you go to a general or small town gym, if you have a good figure, then you will know the correct fitness method, plus you will know and be familiar with diet and nutrition. I'm sure it's okay.
But if it is a regular gym, there will be requirements and maybe a certificate. Let's introduce the qualifications of a fitness instructor.
Fitness instructor qualification is divided into the following categories.
Domestic fitness instructor certification: organized by the State Sports General Administration. At present, there are "fitness coaches" and "aerobics coaches" in China. At present, both of them are divided into three levels, two levels, 1 level and national level.
AFAA: A professional fitness instructor certified by American Aerobic Fitness Association. AFAA qualification certification system has been introduced by 73 countries around the world, taking the lead in establishing an aerobic professional education system in the fitness industry, and its standards have been recognized by the world fitness industry.
ISSA: There are many kinds of qualifications for senior personal fitness instructors certified by the International Sports Science Association. The most famous one is cft certification, which is divided into CFT- 1, CFT-2, CFT-3 and MFS, among which MFS is a master personal trainer.
IFA: International Fitness Association aerobic trainer certification.
AFPI: A certificate officially issued by the Asian Physical Fitness Experts Association. A coach with this certificate can teach in any fitness center in any Asian country.
Although certificates don't mean everything, many times the first impression others have on a stranger is certificates or academic qualifications, so if you want to be a fitness instructor, I suggest you study hard or take part in formal training of these fitness instructor qualifications.
The above is my personal opinion, please forgive me if the answer is not good!