When people talk about isometrics in the training world, they don’t really associate isometric stuff with dynamic efforts for athleticism. Truth is, the isometric concepts/benefits/volume/intensities etc are barely known in the training world.
One could go on and think “why the hell should I train isometrically when the aim is doing dynamic movements?” and, well, he’d be right from a specificity standpoint. That’s not the issue though.
Let’s take a quick example for a more “specific” approach in terms of jumping and dynamic movements. The “athlete” in cause would be, you guessed it – your favorite athlete – me.
Whenever I take a running jump or do any kind of change in direction or whatever dynamic effort, I always am “ready” for the shock of that particular event. I don’t know if you’ve figured it out already, but a lot of people talk about “be ready!” for these kinds of things yet nobody ever defines what “ready” means. Besides of the usual “be aware” definition, “ready” also means “tensed”. So you basically get “tensed” before a dynamic event occurs. According to Yuri Verkhoshansky, this can lead up to a 20% increase in performance in the dynamic movement.
Really, the next time you jump at high speeds be aware of your “preparedness” before the jump. I bet you’ll find out that you’re already tensed up (pre-tensed), just that you haven’t thought about it before.
If not, try to isometrically tense your BODY muscles and see the difference. Notice I haven’t said “leg muscles”, and that’s because it’s a whole body tensing that’s the important thing. The reason for that is the muscle irradiation effect the other muscles have on your stability and power output. This has been bought to my attention by Pavel Tsatsouline but I have found out that I have already been doing all the things he talks about in his book “The Naked Warrior” (more about the irradiation thing in the next article).
So basically, tensing isometrically before an athletic feat (or a power/strength lift etc) is very important. That’s why the isometric training can/must have some emphasis in training for overall athleticism. In the one-leg jump, for example, it really is an explosive-isometric event that is happening – you plant your leg and that leg has to isometrically contract very quickly and stay stiff so you can use it as a “pole” to jump off, like in the pole vault. Of course, that kind of tension is still muscularly generated, so it’s still an expression of good ol’ strength, just like anything else. But you can pump it up a bit more by doing isometric-specific exercises in the gym.
One of my favorite isometric holds is the split squat iso hold using a barbell. Here’s me doing it (video is from 5 years ago):
Now, maybe this variation I’m showing here isn’t the most specific thing in the world to the one leg jump (it’s not at an optimal, specific angle like what happens in the amortization phase of the one-leg jump) but it’s “good enough”. It’s still specific in terms of its unilateral status and quad and glute load (altough the calves and hamstrings play a huge role in the one leg jump – roles that I will dissect in an upcoming article in the next few days).
You should aim for sets of 10-20 seconds for strength gains. You want to bring real intensity and LEARN to tense up good so the next time you tense for jumping it will happen quickly and provide you with good stability for the leg muscles to exert power against the ground, but also (and more importantly) for the leg muscles to properly and effectively absorb the ground shock in the amortization phase.