Why Americans take their shirt off when running?

You could argue that the Americans are behaving more naturally by running in public without a shirt but I draw the line if people are running without shirts on in in urban areas where there are many people walking around because that probably might be somewhat offensive (to some folks), but if you're running without a shirt in natural settings well away from urban areas (on trails, etc) then I don't really see a problem.

It’s funny because I think the perception here is that Europeans have less modesty about their bodies (more nudity in films, nude beaches, etc) than Americans. I think it’s just a big cultural thing here amongst the high school and college running communities. I started running shirtless because my high school team did, and if the upperclassmen had all worn shirts during practice when I was a freshman, I probably would have too.

I will say that the American South in the summer will make you fall in love with running shirtless. With 95 degree heat and 80% humidity, any shirt you wear just sticks to you like a wet rag after just a few miles.

I do it on trails in the UK. When I meet hikers it doesn't bother me too much. Wouldn't dream of doing it in a busy, public place though.

I feel more self-conscious wearing tights during winter when many folk get to see my frozen, shrunken penis.

Because it's cool and feels better. Until I got bigger and now my armpits chafe.

I can only report for myself. I sweat a ton which leads to painful nipple problems if my shirt is on if ambient temps are above 75°. Since I live in PHX, 90% of my runs are shirtless.

its hot

It depends on the person. There can be many reasons. For somebody, it is much better than allowing a tshirt stuck to wet body. I didn't pay much attention to how people run.

I can't speak for others but even into the 40's I run hot and being shirtless makes me feel much cooler. It may be mental but it effects my running when I even wear a singlet if I'm doing a hard effort.

I'm just a hobby jogger too.

I wondered about that myself before I moved to the South.

The humidity can be crazy here. While I run with a singlet in the worst months, I do take my shirt of when I work for 5-10 minutes in my garden. You can soak up a shirt within 5 minutes with easy work, no problem.

So know I understand.

Not sure if it's a cultural thing or other countries have thoughts about protecting their skin. I frequently get asked in my group why I'm always running in a shirt and hat while the entire group is shirtless. It might be slightly less comfortable than shirtless (the degree depending on the shirt though), but personally I'd rather protect my skin.

The better question is why don’t people run shirtless where you are? Not why Americans run shirtless. It should be obvious why running shirtless is better. It feels good, less clothes to get all sweaty and need to be washed, get some sun which is good for you and feels cooler on really hot days.

Have you ever run with a dewpoint of 78 in full sun?

Why do I have to pay taxes from my hard earned pay to support and protect people in Europe only to have them complain about what I am wearing or not wearing?

Why do you think your taxes support and protect people in Europe?

How about my grandfather that is buried in France for liberating it? Let’s start there. Oh, that’s right, you have forgotten.

We have policed the world and that comes with a cost both physically and monetarily. Debate that and I would say you have no idea what you are talking about.

Oh, and to the OP, I will run with my shirt off whenever I please and I will actually take a shower after which I know is also not customary in smelly Europe.

Because we are inferior to our Russian/Chinese counterparts. Is that the answer you're looking for?

It just feels better to run with as little on as possible. Freedom of movement. No shirt, light shorts, light socks and light flexible shoes. Who wants to feel weighed down, especially on hot, sunny days? Some may find our skinny bodies offensive, but...