Not a red flag. This company is amazing and the guy just happens to be strongly into running, so he was genuinely interested and curious, most probably. He runs

Not a red flag. This company is amazing and the guy just happens to be strongly into running, so he was genuinely interested and curious, most probably. He runs a lot. Of course he checked and I can't blame him. It was also not at all a criterion. This was also a side discussion during a technical interview. It was fine, really.