Age group times

Does anyone know the sort of times a 12 year old would run for 100m? Anyone know the UK record for age groups?

You can see under 13 times on the power of 10 site, you can usually see the age group all time lists there to.

Top of the under 13 this year is a 12.21, all time looks to be 11.6! Mind if i ask why the interest?(im assuming fast son/relative)

My friend's son ran 12.56 (12yr old) over the weekend. Cool wet afternoon also and easing up after 80m. Set a PB after little to no training.

Well judging by the list thats a great time! I always wondered what age kids should start proper weight training at for sprinting?

He's not a particularly big kid. His dad's a huge unit though. More lard than anything else. Just a normal 12 yr old who likes to run.

He doesn't do weights yet, just sprint drills, hopping and the like thrice a week.

Very impressive time. Nearly world class to be honest at that age. Curious about the timing method used though?

Re. Weight training... I'd avoid it for another 2-3 years depending upon what kind of weight training you have in mind. You've got to be so careful at that age. So many ifs and buts... Depends upon maturity of the individual and then what kind of regime to take. You don't want to bulk up at that age. So 'weight training' isn't necessary. Especially as the person in question is more than likely to be still growing.

It was hand timing so I'd take that time with a pinch of salt.

I would because hand times are generally given as tenth of a second as in 12.6 rather than hundreths as in 12.56.

Having said that anything under 13.0 would be very quick for an under 13, so good luck to him

azania wrote:It was hand timing so I'd take that time with a pinch of salt.

I would estimate hand timing at about +/- 0.15 seconds. It still an excellent time considering the uncertainty and conditions. They should be running him against the older boys to give him something to aim at and keep him humble over his abilities.

Any coach who asks anyone under the (morphological) age of 15 to do weight training needs to take a long hard look at himself, and either do some remedial work or stop coaching.

Having said that, 12.6 is a very good time for a 12 year old. All the best to him.

The conventional method is to add 0.24 seconds to any hand-timed result.

Speed of sound in air is about 344 m/s. This means a starter pistol at the starter line will be heard at the finishing line 0.29 seconds after firing. Adding 0.24 seconds assumes a speed of sound of 417 m/s. I would guess perhaps some sort of visible signal could be given by the starter - perhaps raising an arm and saying go at the same time as lowering the arm. The timer starts the timer when he sees the arm start to move downwards. In this way there shouldn't be any delay in starting the timer apart from the reaction time.

Of course simple technology could be used - a microphone at the starting line or perhaps some sort of mechanism connected with the starters pistol to start the timer, a 100 m length piece of wire and some gizmo at the finishing line (e.g. a low power infra red beam plus detector - the sort of set up you get with a remote control tv set). Shouldn't be too expensive.

"I would estimate hand timing at about +/- 0.15 seconds."

Why that figure? Is that some generally accepted norm for hand-timing?

Nore, when hand timing an official race, the timekeeper will start the watch when they see the muzzle flash or the smoke from the gun.

The additional time added on I guess is reaction time.

Given that the average reaction time is approx 0.2 seconds.

The timer has to react twice, once with the gun and another with judgement of crossing the line.

Big grey area is a gun isn't used and a hand or flag used for the start (lol)...

So depending upon a lot of factors (that we don't know) there is a huge range for inaccuracy.

However, if judgement by the timer was 'spot on', surely there'd be +/- 0.4 seconds range around the hand clocked time.

Well, of course there are loads of different factors that could influence the timing.

Adding 0.24 seconds to the time is how hand-timed is converted to FAT. Not saying it's always (or ever) going to be completely accurate, but it's just how they do it.

Taking Ryans estimate of reaction time

ryanbailey wrote:Given that the average reaction time is approx 0.2 seconds. ..

Let’s call that ........................[reaction time] = 0.2 +/- 0.1 seconds.

Starter fires the gun at ...........[t-start].
Timer starts the timer at .........[t-start] + [reaction time1].
Runner crosses the line at .......[t-end].
Timer stops the timer at .........[t-end] + [reaction time2].



Actual time .................= [t-end] – [t-start] = [t-actual]
Timer times it as:
[t-timer] ....................= ([t-end] + [reaction time2]) - ([t-start] + [reaction time1]).
.................................= [t-actual] + ( [reaction time2] - [reaction time1])

Assuming [reaction time1] = [reaction time2] = 0.2 +/- 0.1 seconds.



We get: [t-timer] .......= [t-actual] + ( [+/- 0.1] - [+/- 0.1])
................................=[t-actual] +/- 0.14 second
i.e. close to my original estimate (adding errors is something covered at first year UG level or A/S level statistics).


However djloves "addition of 0.24 second to the hand-time rule", which I am certain must be based on actual testing indicates that [reaction time2] can be neglected and so we are left with:
[t-timer] = [t-actual] - [reaction time1].

Hence we need to add [reaction time1] to make the correction. This has been estimated as 0.2 +/- 0.1 second, which on average is +0.2 second and hence close to the "adding of 0.24 second" rule of thumb used to correct the hand-time.

I think we now have consistency.

I may be wrong here but aren't you missing the fundamental point of dj's article?

0.2 is a fair enough assumption of reaction time, but that's the athlete's reaction time not the timer's.

the athlete responds to the sound of the gun but the timer responds to the muzzle flash of the starter's pistol

What with the speed of light being faster than the speed of sound the timer should have started the clock before the athlete moves. That's why I imagine the +0.24 is more accurate IN HAND-TIMED RACES than the +0.14 attributed by yourself.

But I may well be wrong!

Further thought on this one...

The first reaction to the gun/flag etc.. would be +0.2s. Unlikely that the timer will jump the gun.

The second reaction of the timer could 'jump' the runner or rather his/her judgement could, so that could be -0.2s to +0.2s??

Therefore I guess the range would be anywhere between +0.0 through to +0.4s. An median average of +0.2s.

What assumption for accuracy do we take for the timers judgement of crossing the line? +0.04s???

Yes I am having to assume Ryan's scenario, that the only reaction time to consider is at the start and that adds the "0.24 seconds time" of djloves hand of thumb rule.

Added to this reaction time will be the uncertainty that can go either way - at the start because the reaction time is not always going to be precisely +0.24 seconds. There will also be a +/- error uncertainty at the finishing line but not a "reaction time" because the timer can see the runners running and would be able to "predict" the precise moment the runner crosses the line. He won't be able to do that with the gun - so it would be 0.24 seconds +/- something.

However that's as far as I can take it - I will need to go away and find out more on this +0.24 seconds business. Maybe adding +0.24 seconds is being ultra-conservative.

I assume the start of the race is when the starter "fires the gun" - not when the runners "hear" that the gun has been fired - which will vary depending on the lane they are in - assuming a simple "school" system.

Most of the timekeepers in the UK that time at meetings like national champs and the televised events will generally get within 0.1s of the electric timing well over 90% (and often 100%) of the time. The accuracy generally gets worse as you work your way down through lower-graded and less experienced officials down to novices and (dare I say it) schoolteachers! These inaccuracies will probably increase if the "signal" from the starter is poor e.g. a weak "phut" and a wisp of smoke rather than a loud bang and an orange flash.

Inaccuracies in manual timing of sprint events tend to give times that are faster than electric timing or a top manual timekeeper. Recording a manual time to 1/100th second doesn't fill me with confidence as it suggests a certain ignorance of the rules and how to timekeep accurately. However, if the starter's gun has at least a reasonable amount of smoke coming out of it (lots of ammunition doesn't give a flash), and the timekeeper at least is looking at the gun when the race starts, even a very inexperienced timekeeper should be only about 0.3 to 0.4 seconds fast. The worst case scenario of a "pop gun" and a timekeeper who isn't really paying attention at the start (teachers are often prone to this in my experience) could push this error up to something 0.7 or 0.8 fast.

Therefore I would say that this young man's time is worth about 13.3 at the very slowest which is still a very decent time for a 12 year old, especially in poor weather conditions easing up.

The +0.24 adjustment is a standard adjustment used internationally for various purposes. For instance, this adjustment is built into the combined event tables for decathlon and heptathlon (an 11.0 hand time for 100m scores the same points as an electrically-timed 11.24) and I think is sometimes used for qualifying times. It is not appropriate to apply it to British hand times at club level or above.

Yes I am a timekeeper (amongst other things).

Thanks for the additional info

Ryan
"The first reaction to the gun/flag etc.. would be +0.2s. Unlikely that the timer will jump the gun.

The second reaction of the timer could 'jump' the runner or rather his/her judgement could, so that could be -0.2s to +0.2s??

Therefore I guess the range would be anywhere between +0.0 through to +0.4s. An median average of +0.2s.

What assumption for accuracy do we take for the timers judgement of crossing the line? +0.04s???"



I really loved all this. But what the hell is it about?
I would pay money to see a sprint race started with a flag. Would anybody move?

Second reaction? To what? How do you jump a runner?

What range? Where did 0.0 and 0.4 come from?

Why 0.04? Why would you need 100th of a sec in a hand timed race?

And that's just the questions that immediately sprung to mind. But to be fair I did enjoy trying to understand what you said!



Nore, my good friend. You appear to be in a bit of a pickle. Have you actually ever seen a hand timed race?

Hope this helps
http://condellpark.com/kd/reactiontime.htm

I have a feeling it's the sort of thing you'd enjoy.

english_osprey wrote:...Nore, my good friend. You appear to be in a bit of a pickle. Have you actually ever seen a hand timed race?

Hope this helps
http://condellpark.com/kd/reactiontime.htm

I have a feeling it's the sort of thing you'd enjoy.

Cheers EO, I relish pickles, relish them I do. Thanks for the link I note the following from it:

"...He might see a puff of smoke from the starter's pistol just 0.270 seconds after the gun. Hand-timers were trained to react to the smoke signal."

This fits in with the +0.24 seconds mentioned by djlove and trickstat. I am feeling unpickled already

Nore
No problem
Loved the casual juxtaposition of pickle and relish by the way. Fair play!