[Aside from having to shift Ion's weight now and again, Asch doesn't seem to be having much of a problem. He glances at Rick when the other man speaks before returning his eyes to the road - he can identify the man by his voice and stutter, anyway.]

I'm fine. At this point, stopping to switch would take more time than it's worth.

[His words are brisk, but mostly because it's easier to balance his breathing if he's not trying to speak. He does fix Rick with another look briefly, though - it's easy to take it as harsh, especially with his "face" being a wireframe, but it isn't really intended that way.]

Save your strength for later on. There's going to be more people who get tired later.