These cities are relatively flat, relatively cool (watch videos of cycling in Copenhagen and you'll see a lot of people in coats and hats), and you don't have to bike very far to get somewhere interesting. There's also the fact that there's a lot of bikes on the paths (which, for me, caused me to slow down considerably from my typical bike pace when I visited). This all combines to mean you aren't putting anymore effort in than a short walk: you just end up going a little farther in the same amount of time.
Re: the rest.
When I was a regular cycle commuter (in a Canadian city) I did pack a change of clothes, spare deodorant and/or wore a removable outer layer that resisted road gunk. Road gunk is _much worse_ on any route you share with cars. Dedicated bike paths tend to be quite clean. Paniers are far better than a backpack, since they sit on the bike frame, you barely notice the weight. But as other commenters noted: a little fitness goes a long way. After a year of commuting, my regular route wouldn't even cause me to break a sweat.
These cities are relatively flat, relatively cool (watch videos of cycling in Copenhagen and you'll see a lot of people in coats and hats), and you don't have to bike very far to get somewhere interesting. There's also the fact that there's a lot of bikes on the paths (which, for me, caused me to slow down considerably from my typical bike pace when I visited). This all combines to mean you aren't putting anymore effort in than a short walk: you just end up going a little farther in the same amount of time.
Re: the rest.
When I was a regular cycle commuter (in a Canadian city) I did pack a change of clothes, spare deodorant and/or wore a removable outer layer that resisted road gunk. Road gunk is _much worse_ on any route you share with cars. Dedicated bike paths tend to be quite clean. Paniers are far better than a backpack, since they sit on the bike frame, you barely notice the weight. But as other commenters noted: a little fitness goes a long way. After a year of commuting, my regular route wouldn't even cause me to break a sweat.