When I was stationed in Germany, one of my favorite things to watch was the strongman competition. Sure, it was broadcast in German, but I knew exactly what was happening when the BIG guy strapped himself to a firetruck and pulled it while willing his knees not to give out.
So, the group I run with incorporates this type of training into our schedule. Just not intentionally. It seems we have somehow always 'found' a vehicle to push during a run - perhaps a half dozen or so in this past training season. Which is understandable on long runs - somewhere in 20 miles, there is bound to be a stranded motorist.
Tonight, however, was a shorter (5 mile) cold run that we were all hustling to finish. And then we happened upon the poor guy who ran out of gas a couple of blocks from the gas station, and whose young son was unsuccessfully trying to push the SUV. Anyway, we took a break and pushed him to the station, walked for a bit to recatch our breath, and finished the run. Definite strongman style. Now I just have to figure out how to incorporate their "keg throwing" event into running.