Although I am one of the slowest hikers around, only very slightly faster than our native banana slugs, I often pass people (mostly tourons) on our steep Columbia Gorge trails. Why? Most of them dash up the hill as fast as they can, then stop several minutes to gasp for breath (that technique plus the lack of daypacks is how I know they're tourons). They pass me when dashing and in turn I pass them while they're gasping. I set a slow and steady pace that allows me to keep going without stopping to catch my breath. It's extremely slow, but it often gets this tortoise to the top of the hills ahead of the hares! While I don't say anything but "Hi" or "Hi again" when we meet, I have noticed that a few of them have gotten the idea and slowed their pace. Those folks generally do beat me to the top!

I have seen the phenomenon Balzaccom describes, of course! On the other hand, when far enough from the trailhead to avoid the tourons, I don't think I've ever passed anyone! I've also seen it on the highways when I start to pass someone (inevitably a male driver) who speeds up as soon as I'm alongside him where he can identify me as female. Never mind if they were poking along at 10 mph below the speed limit when I started to pass!