What does banter mean here?

Having some funny talk with each other while having a run.

The joke here is that he was enjoying banter, light casual conversation, while running at a pace that most people couldn’t sustain for 10 seconds for 2 hours straight.

banter is joking around, having a laugh. often, it also involves making fun of each other, but in a playful, friendly way.

Talking back and forth. Can be witty banter, silly banter. A good flowing conversation.

Means the same thing here as it does everywhere. https://www.merriam-webster.com/dictionary/banter

Means the same thing here as it does everywhere. https://www.merriam-webster.com/dictionary/banter

Means the same thing here as it does everywhere. https://www.merriam-webster.com/dictionary/banter

here's some banter : you sure run in a fucking straight line

Banter is casual conversation. Peers at work, friends, students, etc., banter and "tell jokes, use sarcasm, etc." You don't banter with the Queen of England or a judge.

Was it necessary to use black emoji when describing a part in England?

Thats the only definition of banter that I know of. Its British English for a particular kind of conversation or interaction. One where the participants are making jokes and taking jabs at one another. BANTER:" to speak to or address in a witty or teasing manner"

Of course the banter is going to be light if no one is fast enough to keep up with you😅

It means the same thing it usually means.

He ran an average of 21km/hr for 2 hours straight, which is a pretty fast sprint speed. Banter is casual conversation. He's joking that he was able to carry a conversation while running a very fast pace for a long time.

Banter is a lighthearted joking type of conversation

The banter between them was good this morning. Banter often equals light teasing in a fun manner.

banter = light conversation.

It's whenever you talk to someone like a friend in a casual, informal way.

Banter generally means informal chat, however as a native speaker I dont associate that word in this context with simply chatting. I’d read that and think they’re talking about their overall run experience.