No registration fee can be charged. As a commercial activity, gymnasiums must obtain a business license and register according to law before they can operate legally. If the gym charges a registration fee without obtaining a business license, there may be a risk of illegal operation and it may be investigated and dealt with by relevant departments. If the gym does not obtain a business license, it can not guarantee the quality and safety of its facilities and services, which may pose risks to the health and safety of consumers.