dealt_with, by swear by I meant Kelly Pavlik and some others whose name escapes me having it as part of their routine in training camps for several years and partially attributing their functional (though I know you loathe that word) strength to it. :conf How about wood chopping, as Mayweather did in prep for Pacquiao, another "old school" training exercise?
Again, it's just another general power exercise that is going to have some transfer across to punching, but isn't sports specific. No better or worse than something like throwing a med ball against the wall. Just another tool to achieve the same thing. Those sort of exercises aren't going to improve anyone's strength, they'll improve balance, coordination and RFD to an extent so they could give the illusion of increasing what some people call 'functional strength' (which actually means nothing and makes no sense).
If that's what you want to do for your general conditioning that's fine IMO, you're mixing muscular conditioning (tyre flipping) with your cardio conditioning (sprints). That sort of work is very fatiguing and again it doesn't have direct transfer to boxing, so it's best done a fair way out from comp during your general prep. That sort of thing is fine for creating a physical base before the more sports specific conditioning. People need to remember the most important thing to get conditioned for boxing is actually boxing. I've seen guys who run and do circuit training all year round wonder why they can't box at a high intensity for a prolonged period of time. They don't allow fatigue to dissipate and they don't focus on what's really important.
Yeah, there's no substitute for the bare essentials (bag work, mitt work, sparring & shadowboxing) :good The combination of strength exertion with cardio with no respite in between has to at least have some transferable value to boxing, though? Even if the movements themselves aren't quite a direct simulation, it does acclimate your body to quickly transitioning between two very demanding but very different types of activity - which is something that comes up in the ring. (fighting in a clinch one moment, switching to evasive maneuvers the next, etc)
For sure, you're heavily stressing the glycolytic energy system which is the predominant energy system during boxing so there is good transfer, that's why that sort of thing is great for general prep. It will make the transition to sports specific conditioning a lot smoother but it shouldn't be viewed as 'conditioning for boxing', it's more 'conditioning for conditioning for boxing'.
Got introduced to the sledgehammer and tractor tyre by my father and my boxing coach's - today I find a small truck tyre to be the best. A good handle length sledgehammer, reasonable weight, well maintained. It can really click as a good benefit for some guys who just can't get in their head that they need to help themselves and their coaches by living strong out of the gym as well, gives quite a few of them the old home maintenance spark and go out and do a regular weekends yard work instead of getting ****ed. From experience people love sledgehammers and compacted, dirt mounds to pound down. Lays a lovely putting green or cricket pitch as well. Also great for taking frustrations out by including in circuits of manhandling tyres, wrenching / stretching old bike tyres / inner tubes. For yourself one of each, for a gym three or four depending on size IMO and your right.