For those of you who are foreign, non-native English speakers, or possibly retarded, "wherefore" doesn't mean "where"- it means "why". The misuse of this word annoys the tits right off me, so stop doing it.So, the wherefore for the Overhead Walk- it will probably boil down to boredom and curiosity. I started doing them initially because my old roommate and I started taking a bunch of plates and a barbell to the park on Saturdays, grilling a shitload of steak, drinking a tremendous amount of liquor, and lifting for a few hours. We ended up getting bored with cleans and snatches and the like, so one of us decided to snatch 135 and walk with it as far as they could. When they ditched it, the other one of use would yank it out of the ground (where it would be deeply embedded) and then walk as far as they could. We'd do this for an extraordinary period of time, and left us sore as a motherfucker the next day. Given a preference, that's how I'd still do it, outdoors, over uneven ground, drunk, and to death, but I lack access to both a masochistic training partner and barbells and plates I can take outdoors, I'm forced to do it inside by myself (as will happen occasionally to the best of us). Which means I go as heavy as I possibly can, because fuck cardio anyway.
For those of you who want a little more reason for the things you do in the gym, you'd do well to remember that many bodybuilding pontificators and some sports scientists (among them Dr., Charles Staley), emphasize the time during which one's muscles are under tension as a critical part of program design. Clearly, as I spend the vast majority of my considerable time in the gym lifting as violently and briefly as possible, this is not a key component of my training. I do, however, believe that it is a fairly good indicator of training volume, and thus should probably not be completely ignored. This type of exercise will drastically increase your time under tension, as it's a sort of combination static-hold, microrep partials, and endurance exercise all rolled into one gigantic bag of awesome.
As to the how, it's fairly simple- you clean and press or jerk, or snatch, a weight overhead and then walk with it until you don't feel like it any longer or cannot. I enjoy using a variety of rep ranges, weights, and techniques for this type of exercise because mixing this sort of thing into a workout is all about spicing shit up a bit. Like just about every other facet of training, this is hardly rocket science- just figure out what you like and do it. A lot of it.
As to the when, Overhead Walks are a nice way to mix it up, give you something to do on a day you want to train but have no idea what you want to do, or are spending the day in the park grilling, drinking, and lifting. I do them very infrequently (like, once a year), but I always enjoy them when I do them. If I did them more often, I'm certain I'd have no problem going heavier with them, but I'm far too focused on other lifts right now to get sidetracked with this silliness. For those of you who are already winding up a nice cry about how I walk around with more weight than you overhead press and you could never do this and blah di fucking blah blah- suck it the fuck up and press more. When you're pressing, make sure you lock out each rep and hold it. If you do that, walking around with heavy weights overhead's easy as fucking on a dead bear.
SHAKE THAT BEAR.