Walk 1.25 miles carrying two 25 pound plates.
The plates are the kind with wedges cut out of the center, so you can easily hold them by the rims. I had to stop once for a shoelace and once to get rid of a fly, but didn't need any breaks for my grip or shoulders, which was a little bit surprising. I've done this walk with one plate before, and that's pretty easy, but this was the first time I've tried two.
I'm a big fan of the paleo/evolutionary fitness concept, and I find it consistently interesting that every paleo "guru" has his own ideas about how you should exercise.
Art De Vany is all about short high-intensity workouts, and he uses a lot of machines in his routines.
Frank Forencich (Go Animal) talks a lot about playing, and how exercise should be natural and fun.
I have my own ideas -- different from both De Vany and Forencich -- that are mostly theoretical at this point, since I haven't really had time to test them on myself. I'll be happy to share my thoughts if anyone is interested.
The one thing all paleo guys agree on is that cavemen walked a lot, and they usually did it carrying some non-trivial weight. This is a very roundabout way of saying that I decided to mix in the occasional weighted walk because of my paleo interests. I'm not sure how often I want to do this, since this kind of load bearing can be hard on the joints. Probably no more than once a week, increasing the distance or load very gradually.
We are each an experiment, and every workout is another data point.
"The enlightened never cease forging themselves."
-- Morihei Ueshiba