The issue I take with it is I don't understand how you would program/monitor progression.
Like, let's say I decide I'm going to do farmer's carries with 225 per hand for 1 minute.
Day 1, I do my 1 minute of farmer's carries. I manage to travel 180'.
Day 2, I do the minute of farmer's carries. I've having a real rough day, and I shuffle my feet a total of 5' before the minute expires.
In both cases, I did 1 minute of farmer's carries, but one was a VASTLY superior workout than the other. I feel like it would be more beneficial to have a distance goal to travel and just keep upping the weight or reducing the amount of time it takes to get there.
Otherwise, I do timed holds for grip, but I don't walk anywhere with it.
EDIT: I suppose you could monitor total distance traveled for the span of 1 minute and try to beat those records every workout and also add weight to the 1 minute. Just feels odd to me, like it wouldn't really promote fast footspeed knowing that it's still a minute of travel regardless.