List of the gyms in a country

How to extract a list of the gyms in a country (gym name and city)? Have seen that there are different tags referred to it, like k="leisure" v="fitness_centre", k="sport" v="gymnastics or k="amenity" v="gym".

Note: New to OMS. Have played a bit with the command line (e.g. $ omsfilter germany.oms ... | omsconvert - --csv=...), but would thank if you can provide the full command.