oh, well i feel it is important to contact the board far ahead of your COM...so that will not change...my perception of where the board however, is the big deal...so hopefully that will be much different…
oh, well i feel it is important to contact the board far ahead of your COM...so that will not change…
What does everyone think about that?
Nick and I have actually spoken about it. I personally don’t COACH sticking the takeoff foot out in front of the body but Nick likes the cue and even when he does it to the max it still isn’t I would consider a problem so I don’t worry about it. Personally, I recognize that the takeoff foot of a long jumper has to be out in front a little to create lift at takeoff. There are videos of Nick jumping on YouTube and you can see for yourself that he’s nowhere near Dwight Phillips land as far as putting the foot out in front. It’s kind of a case of not worrying about things that aren’t problems.
yeah, i went to a doctor today at school...she said i dont have infection, but maybe to lay off creatine for a while? she didnt seem to really know…
Also, about the take off issue...The slower the jumper, the more height he must get. I think we can all agree on this. Im not saying im “slow” but im not Dwight Phillips fast either, therefore my take off needs to be in a position for me to get height. In the case of Dwight, because he is SO fast on the runway (11+m/s) (or was in 2004) he has lots of room for error. IF he hits that take off with great height, he will jump huge like his 8.60m. If he doesn’t, he will still go 8.20m because of his speed.
The slower the jumper, the more height he must get. I think we can all agree on this.
I wonder if this is really true. I am not a physicist or aeronautical engineer, so maybe someone out there can say whether the optimal shape of the parabolic curve in LJ varies with speed.
“Why would it not be true? Distance is either caused by horizontal velocity or take off angle...preferably BOTH”
Well, for sure it is not that simple. Take-off angle affects horizontal velocity. For example, the basketball player dunking at the end of a fast break uses a steeper take-off angle than a long jumper at the board. The basketball player thus gets more height but travels less distance forward, exactly what he wants. So, the real questions are what is the optimal take-off angle (and parabolic curve of the COM) for a long jumper, does this vary from jumper to jumper, and does this vary with the speed of the jumper. You said the that the slower the runner the steeper the optimal take-off angle. I am just curious as to what you base that on and whether it is really true.
ex400...Tell me then, in your opinion how a slower jumper can jump the same distance as a faster jumper? And i’m “getting” this from, practical experience, coaches from all over the world, research, obserations...To be honest, i think is is incredibly obvious, that if you are a slower jumper, you need a big take off ankle to jump as far as a faster jumper.
Since speed is a paramount factor in long jumping, it is clear that a slower runner has to be technically superior to the faster one in order to jump the same distance. Technically superiority could include speed at the board (as opposed to speed on the runway); better control of in-flight rotation; better extension on landing; and “better” take-off trajectory. “Better” means closer to optimal, not necessariy steeper. Let me turn the question on you: if a steeper take-off angle will enable a slow jumper to go farther, why would it not also help a fast jumper to go farther?
You are still stating as fact that the slower you are the higher you should jump. I am not saying you are wrong. I am genuinely curious to know why, in terms of the force vectors or however you want to look at it.
As I recall, research has shown that no jumpers achieve a take-off angle that is as steep as physics theory would call for. But I do not see how this is a bigger or different problem for slower jumpers. If it is, I want to know the reason.
So far a given Range, let’s say 8 meters, a guy moving 8 m/s would have to be in the air for 1 second, while a guy moving 4 m/s would have to be in the air 2 seconds. Of course, to be in the air longer you must get more height. So what Nick said about a slower guy needing to get higher to achieve the same distance is true. Of course the only problem is, I’m not sure how you obtain more initial velocity in the Y direction without moving faster. However, I’m pretty sure that the optimal take-off angle would be 45° regardless of your speed.
edit: I don’t know how to make the html in my post work but hopefully you guys can read it…
Take off angle as in 45% for the physics theory you mean? no of course not because our COG isnt on the floor, its half way up our body. Therefore 18-24 degree take off angle is ideal. The faster the jumper the lower between 18-24 degrees the jumper can take off and still produce optimal distance. And yes, of course IF a super fast jumper can take off at 24 degrees then boom, new world record. Look at Powell, on his WR jump, great speed and great height, But that is rare. Pedroso had a consistanly big take off angle, 24 degrees + and he also ran around 10.5m/s which is fast, but not carl lewis, phillips or powell fast. But pedroso was still able to jump 8.50m easily…
There have been some jumpers who have a had a higher take off angle, but its rare and not ideal. Clearly, if i ran 9m/s and had a take off angle of 30 degrees, i wouldnt go very far, just high. But i am talking relative for the long jump. The majority of jumpers take off with angles of what i said earlier.
The UK athletics biomachanics man told me pretty simply one day. He said, there are a few ways of jumping 8 metres. But if your not fast, you better make sure you jump high. And even with great height for 8m metres to be possible you need a velocity of at least 10m/s.
