What is the best all around martial art to improve your physical health?

[Gerry Seymour]

There is training hard, and then there is training hard efficiently. Ultimately, as much as anyone can manage, they must absolutely make training as measurable-by-numbers as possible. You don't want things to enter the realm of linguistic vagaries. If you do, you have macho-minded wrestlers thinking they "worked hard" when the only muscular stimulation they did was equivalent to deadlifting 100 pounds.

I guess it was a bit unfair for me to say that "suplexing people is ineffective", but the point remains. Training in a controlled environment, controlled intensity, controlled volume, controlled pacing, is far more effective than random hard work in some activity.

For example, although I would never doubt that hard-working manual laborers like farmers or construction workers are strong and have gotten strong through their hard activities, I would still consider formalized weight training to be much more effective than what they do. In formalized weight training, you get to measure stuff. And that's extremely important in training.

You're arguing maximum effectiveness, and wording it like that's the only option for fitness. There are lots of ways to get reasonbly fit (and even more ways to define that) which are not the maximally efficient way. Most folks enjoy those more, making them quite useful.