I reply in English as my German is rather poor. Berlin is too far to join you in a naked jogging although I would love to. I practice it regularly when I am on vacation in the south of France in the Massif des Maures. I have never faced any problem with the people I met. Indeed, I run early in the morning to avoid the eat and in remote tracks. Therefore, I met very few people but those I met has never made any bad remarks. The time in the day, the location and my behaviour is cleary without any ambiguity.
In August, I made a nacktwandern in the Eifel PArk in the vicinity of Rotgen. Same, the people I met has always been very friendly. I notice, that, people are more and more open to unambiguous nudity and the risk of being agressed seems to be limited. But be carfeul anyway, you never know.