An interesting article/ book snippet on running anthropology and physiology, including this copy paste below pondering the pendulous male bits and how they relate to the activity. Do your balls retract like this? I don't think mine retract like that, maybe shorten a bit? I don't think i have...
While traveling in Scandinavia, we stopped in a Bed & Breakfast in Ringebu, Norway. It is not far N. of Lillehammer, where the 1994 Winter Olympics were held. Beautiful glacial valley.