Within law, we distinguish among penal law, regulatory law, and property law. In case law, we repeat that distinction, as far as we are aware of regarding judgments.
Common to all utilisations of the term "endangerment of the (general) public" in legal practice is, that it describes a serious, latent danger to the life or physical condition of one or more people – but simple nudity, as it takes place in a nude hike or an athletic activity in the nude, does not cause any (serious) danger at all.
Therefore, simple nudity does not fulfil the fact of "endangerment of the (general) public".
By looking at penal law, we see, that simple nudity is not a criminal offence: In penal law, all offences, that may be related to nudity, concern sexual deeds in public, only. Conclusion: In Germany, penal law is not applicable to mere nudity (as in nude sports, nude hikes etc.).
We are not aware of a judgment regarding nude life and property law.
The German Ordnungsrecht [en: regulative law] comprehends the entirety of all law, which serves to protect public security and order against dangers and disturbances.
We have discovered a regarding judgment.