I went on a guided climb of the Grand Teton several years ago. At some point above treeline the guide pointed to a bunch of large-ish (1-2 nalgene bottles in volume) smooth stones, and asked "why do you think river stones are in a place that's never had any rivers?"
Lots of guesses from the group about tectonics and whatnot.
Finally the answer, "Alex Lowe used to carry them up in his pack when training. He didn't want to hurt his knees on the descent with the extra weight, and this was his turn-around point".
Brings back memories of carrying 20kg of caving gear and ropes up the mountain. Still, I find ascending the rope with a jumar and croll to be the most exhausting exercise I've ever done.
