Thoughts on turn running

Short answers to your questions are (i) I know of no good science papers on turn running (not something I've ever looked into), and (ii) I know naff-all about track running generally.

However, I'd like to offer some thoughts just in case they might help you think about the physics.

First I'll mention that I dislike talking solely in terms of 'force' as that term is not always specific enough. Force is defined as the rate of change of momentum (F = d(mv)/dt) and sometimes is referred to as an unbalanced or dynamic force. But we also use the term force in a static situation where there is no momentum transfer; for example when you are standing motionless on a set of scales. This static force represents energy storage within a material (in a set of scales, elastic potential is stored in a steel spring or similar).

You can see this if you do the dimensional analysis:

F = d(mv)/dt

F = [kg][m][s]^-1/[s] - I like to think of this as 'momentums per second'

= [kg][m][s]^-2

but E = [J] = [kg][m]^2[s]^-2 - dimensions of energy, substitute into the above

Hence F = [J][m]^-1 - think of as 'Joules per metre', i.e. an amount of energy stored in the length of a material

I know it probably doesn't read very well typed out but bear with me. I'm just trying to hammer home that sometimes force is the transfer of momentum and sometimes it is the storage of energy.

You made a comment about how much force is required to run forward at a constant speed. As I'm sure you know in the absence of friction no (unbalanced) force is required at all to maintain speed and during straight running ideally the majority of force production is the storage and return of energy through elastic return and only a small amount is momentum transfer where we 'top up' momentum lost to friction. During a turn however it should now be obvious that we have to completely reverse the momentum (same speed, opposite direction) and so the components of force production are in different proportions. That is, the proportion of momentum transfer to energy storage is different.

I'm speculating at this point but having re-read Noakes recently I'm of the opinion that the situation you describe is due to turn running placing such a high load on the contractile proteins of the sarcomeres for force production (energy production), which is different to straight running where some of this load is taken up by the structural proteins in muscle that provide elastic return (no energy production, just energy return). I'm not going to claim to have anything more than an amateur interest in exercise phys so if you're knowledgeable in that area then please do let me know your thoughts on that.

I'm very hesitant to offer advice since you're the track runner and I'm not, but from the perspective of my notepad I'd say this is a problem of power production. To me your force model strikes me as focusing on the elastic return/running economy side of things. I'd like to try to persuade you to really realise that you're reversing direction and hence the important acceleration is coming from force production that requires energy production rather than energy return. We can't use energy stored in the muscles to change direction: we have to generate new energy.

I suspect you're right that your brain will figure out the best amount of lean. The only possible suggestion I could come up with is to train for the 'sarcomere load', which means training acceleration.

I'm not that interested in turn running myself but I'd be interested if you know of any good treatments of running mechanics generally. I've yet to find a treatment that I find satisfactory. Cheers and good luck!

80kg? Dude, lose some weight.

Running a turn depends on speed and track. If its outdoor, and 800 or slower dont think about it too much. 800, perhaps a slight lean but thats all. Faster, a clear lean, but important not to only lean with your neck. Common mistake. Shorter lift of inner arm.

Lose weight? No way. Bigger is faster in sprints, ask Juanto or Angelo.

Not thinking about it enough is the problem. It kills my 300's. I have no trouble starting on a turn, or holding form in a 400 when I'm already well below top speed, but hitting the turn at top speed is different. 8 m/s requires 8^2/7^2 = 64/49 = 1.31 times as much acceleration to get around the turn as 7m/s.

In races of course nobody actually hits the turn at top speed (except HS 300 hurdles maybe), and I'm sure it's easier to corner when you're not all-out because you have energy to spare. But I'm convinced that perfecting the form in training will trickle down to improvement at slower speeds and improve my split differential.

Balance, equilibrium and proprioception is a bigger issue than most runners think. Most people adjust their form using visual cues. If you find a safe place with no potential obstacles where you can run for 10-15 seconds with your eyes closed, I gar-on-tee you will not run a straight line without practice, and your form will feel erratic and weird.

What are you running these 300ms in? Ever filmed yourself running a turn hitting it in top speed? Personally I rarely hit the turns at top speed (unless I'm training on an indoor track) but lean as much as you can as long as it feels natural.

elaborate troll

Typically I'll run a couple of 26 200's, recover, and then split 28 on the way to a 43 flat. About 2 seconds slower than it should be, and the 3rd 100 is almost as fast as the 2nd. So it's the turn that's eating it up.

Another option would be to go from the 200m start to the 1500m waterfall.

Bad Wigins wrote:

Typically I'll run a couple of 26 200's, recover, and then split 28 on the way to a 43 flat. About 2 seconds slower than it should be, and the 3rd 100 is almost as fast as the 2nd. So it's the turn that's eating it up.

Another option would be to go from the 200m start to the 1500m waterfall.

Ive never heard anyone having much problems with a turn. You'll lose some speed obviously but there isn't much more to id than lower left arm sving, lean in with your hips and power trough them.

Accelerate, work hard trough turn, 'float' last 100.