Group fitness may further be classified into self-organized groups and organizational groups.
Self-organized groups are formed when a few people known to each other through family relationship, work relationship or friendship get together to carry out group fitness. Here the groups usually tend to be small and very cordial. In such groups you show up not because of commitment but because you want to be with the group and you are usually looking forward to it. There is comradeship and fun.
Organizational groups are formed when people usually unknown to each other get together to carry out group fitness in a organizational setting like a gym or a yoga studio. Here the groups usually tend to be larger than the self-organized groups, not so cordial and can be distant. In such groups you are more likely to back out from a workout because you don't feel up to it. There may be comradeship but not necessarily fun.
The linked article doesn't differentiate the groups as we have done above.
Source of shared Link