We all “know” that great one leg jumpers (with a few exceptions) are pretty skinny and light. We all talk about how a low bodyweight, even regardless of strength and relative strength is important in a one-leg jump. Yet nobody identifies why that is? Why is a low bodyweight that important to jumping high off one leg.
Well, for one, jumping off one leg is more about structure and levers than strength. And to gain strength you will, from a point on, need to gain muscle and muscle = weight that needs to be thrown up in a one leg jump. OK, we get that. But anything else?
What I personally think is the answer to the question is actually our mistaken focus on relating strength to squat strength. When we say “how strong is Athlete A” we usually list a number of squat strength and compare that to his bodyweight, thus obtaining his squat to bodyweight ratio:
Athlete A squats 400 lbs at 200 lbs bodyweight, hence his squat ratio to bodyweight is 2.0x. 2 times his bodyweight. We just take that and ignore everything else. So what would “everything else” be?
Well let’s take this: same athlete, yet with different bodyweights and squat numbers, but same ratios:
Same athlete, 150 lbs bodyweight, 300 lbs squat
Same athlete, 200 lbs bodyweight, 400 lbs squat
Considering these variables, he has the same exact squat ratio, and the same exact structure (since we’re talking about the same individual here) – so what “version” of himself will jump more off one leg? From a mathematical standpoint, he’ll jump the same in each scenario. But from a real world perspective, he won’t. Unless he has other numbers the same as well.
Where I’m trying to get with this? Well, it’s the calves. The calves have been so neglected lately it’s not even funny. I’m talking about athletic improvement articles – they all reffer to upperleg/hip muscles as far as strength training/importance in athleticism is concerned. Which is correct – they are of major importance. But let’s take our example:
Version 1: 150 lbs bodyweight and 300 lbs squat. Yeah, but how about his calf strength? How much can he calf raise with perfect form and full ankle extension? Let’s say he’s good for 300 lbs x 10 reps perfect form.
Then take Version 2 of the same guy: 200 lbs bodyweight and 400 lbs squat. Cool, but has he developed his calves to the point where he can do 400 lbs x 10 reps perfect form as far as calf raises are concerned (or better yet – as far as calf strength is concerned)?
You see, the one leg jump is a very “shocking” jump for the joints and muscles, that actually contract explosively-isometric in the amortization phase to lock the jumping leg and create a pole out of it for good leverage purposes. The forces that appear in the plant are up to 8-10x bodyweight. The injury risk also increases a lot with an increased bodyweight if a firing fail occurs in a muscle (which happens from time to time).
So if we take the 150 lbs guy with 300 lbs squat and 300×10 calf raise strength and establish that as “good calf strength”, what happens with this same guy that weighs 200 lbs and squats 400 lbs but can’t do 400×10 calf raises (hasn’t enough calf strength)? Well, a break in the chain will happen. The ankle will collapse, allowing the tibia to go forward in the plant. When the happens the knee gets under tension and the quad gets under tension. The knee goes forward and the hamstring LOSES tension (both because the knee goes forward (so the hamstring is shortened) AND because the quad gets tension, and since the hamstring is the quad’s antagonist, it needs to relax as the protagonist (the quad) contracts). The hamstring, losing tension, will also produce less help for hip extension purposes which will overload the glutes.
So – just because the calves failed, you have: no calf strength to propell the ankle, quad overload, hamstring loss in tension, glute overload (assuming the glutes work well in the first place).
Try this – get with your back against a wall. Then put your feet in front of you, legs completely straight. Your legs to your hips should be at a 45 degree angle. Like this /. Then really really push with your calves like trying to raise on your toes. Try to relax your quads completely and just focus on pushing with your calves, trying to “rise” on the toes (although you won’t since the feet are in front of you, feet also flat on the ground but at an angle). You’ll notice that even though you don’t really tense the quads you’re able to maintain a straight leg/extended knee. So not a lot of knee/quad load. This is when the calves work. If you relax the calves (as in they are not strong enough for the task of keeping the ankle extended (plantar flexed)) you’re going to find yourself in a ton of quad overload/knee overload.
THIS ^^^ is why you need great calves. But the problem is – they can only get so big. You can increase your squat a lot and the calves won’t be able to keep up. You might get them a bit bigger/stronger but they won’t keep up with the squat increase since the squat depends on many muscles and they all develop at the same time, so the squat will increase easier and faster.
So you’ll end up with maybe an even bigger squat ratio than before and you still won’t jump higher off one leg. Was it the squat’s fault? Or the fact that you’re stronger? No, absolutely not. It’s the problem that the calves haven’t adapted yet. Or maybe they’ll never will, who knows?
But for lower bodyweights, the calf strength is less of a problem. This is what is really going on.
Also, like I said, being heavier means a much “better” chance of injury if you have a firing issue. If the plant shock is 8-10 times your bodyweight, and a muscle doesn’t fire when you plant, the overload occuring on the joints is 1500 lbs for a 150 lbs person vs 2000 lbs for a 200 lbs person in the case of a high speed, 10x shock. That’s 500 lbs of additional force being casted into the joints, which translates into a higher chance of injuy.
So the next time you squat, don’t neglect your calves!
