J.O. wrote:
I do two footed jumps rather than hill springing. I do a few bounds, but not a lot. The danger of injury from any type of plyometric work is quite high, so I am ultra cautious.
Gosh, J.O., when someone asks about Lydiard hill training, you just can't help but butt in and talk about YOUR hill training, don't you? Just kidding; I'm just giving you some $hit! ;o) Forgive me.
Actually you're right and there's nothing wrong with two-footed jump. In fact, when Lydiard came to Japan in 1991, he showed this very exercise and called it "frog hop" and his assistant, Helen, did the demonstration and I have the article with the images. The only thing is; if you do it this way, and if you actually go all the way down in a squat position, your knees will get a lot of stress and may lead to some knee issues. Plyometrics is plyometrics; you can do it as a "frog hop", you can do it like "depth jump" like Seb Coe used to do. You can do it like one-leg hop or whatever. The thing you'll need to remember is; that he placed hill training as a mean to add onto yet another element in development. In other words, with what we call a Lydiard Pyramid, you develop your aerobic capacity first with long slowish coneinuous running; then comes hills to introduce power and flexitility in your legs AS WELL AS maintaining your well-developed aerobic capacity. In other words, and Lydiard had said this many times over, if you want to introduce power and flexibility by lifting weights, that's fine too. But you have several tasks at hand during this phase; (1) to introduce power and flexibility in your legs; (2) start to teach your body to exercise anaerobically to slowly introduce some faster running; (3) maintain your aerobic capacity development. In other words, once again, if Lydiard placed his hill training between Marathon Conditioning and Track Training and you're supposed to fulfill these above points, but you decided to go off tangent and decided to just work on your leg strength, well, you're not going to be ready for "Lydiard" track training; you might as well follow some other training program because now your whole program is not going to be balanced. You can still work on weights of gym (jumping, hopping, whatever) as long as you do long runs to maintain your aerobic capacity and do some strides or something to introduce some faster running. All these things, as Lydiard had reasoned, if you have lots of time to do all this, fine. But back then, Arthur's runners had to work 40 hours a week and they really didn't have time to waste; the best approach to get all these at once was a type of hill circuit he advocated.
Now, going back to the original question; I wouldn't really try bounding or springing unless you're a middle distance runner. I think marathon runners benefit so much more if they work on long steep hill and do the steep hill running (like that Seko's footage I posted on facebook). Bounding/springing is really hard on your legs and tendons, as J.O. pointed out, unless you know you can handle it well, I wouldn't recommend it. Of course, the rule of thumb in running training is to move from high volume low intensity to low volume high intensity. You should do the same with hills too; if you're not used to this kind of exercise, do long hill and just run up with exaggerated knee lift and ankle snap. Gradually, as your legs get stronger, do shorter hill and more demanding exercise as bounding or springing. If you want to do it that way. I'm sure Arthur would have answered: "Do what you feel comfortable with, as much as you feel happy about..." I really don't know how else to say given the fact we have no knowledge of your background; event you're training for, how much of this kind of exericse you've done, or a former triple jumper...
The difference between bounding and springing is not that much. I always view that as more to do with the available hill. If you have more long gradual uphill, bounding is more appropriate; it's hard to go up and down like a pogo stick on gentler hill. If you have short steep hill, springing is good. Basically, if you go up and down more vertically, that's springing and it works your ankle really well. If you leap forward horizontally, it's bounding. Good knee lift; back leg extension. Understand your weaknesses and strengths and modify the exercises accordingly. Otherwise, you may follow a program blindly but you won't get anywhere.