DCM 2013: Mentored Novices Thread......Take 2

SnailsPace

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Today we’re turning our attention to the role of wind resistance in aiding or impairing performance, a topic that’s only received spotty coverage over the years.


Research on the affect of wind resistance and running performance
The first study we’ll look to was published way back in 1971 by L.G. Pugh, a researcher in London.1 In his experiment, he had his subject (there was only one, an international-caliber middle distance runner) run along a treadmill cleverly mounted inside a wind tunnel.

Pugh measured the oxygen consumption of his runner over a variety of running speeds and wind velocities. He found that oxygen consumption, and therefore energy cost, increases with the square of the airflow over the body. So, the performance hit of a 10mph wind is four times greater than that of a 5mph wind, and the additional resistance running into a steady wind at 5:40 mile pace is twice that encountered when running into the same wind at 8:00 mile pace.

In an additional experiment, Pugh measured the oxygen consumption of his runner first while running alone into a headwind, then while running one meter behind another runner. The result? An 80% decrease in wind resistance when drafting off another runner! This corresponded to about a 6% drop in oxygen consumption for the given pace.

Pugh confirmed these findings by taking airflow measurements in the wake of a single runner, then computing the effective air resistance for a runner-shaped object one meter back. From his measurements, it appears that there is still some benefit from drafting even two or three meters behind another runner.

In a later study published in 1980, C.T.M. Davies investigated the effect of headwinds and tailwinds on three subjects using a similar treadmill-in-wind-tunnel setup.2

Like Pugh, he found that oxygen consumption increases (and therefore, performance decreases) proportional to the square of the wind speed.

Furthermore, while a tailwind does aid performance significantly, you only “get back” about half of what you put into a headwind when you turn around and run with it at your back.

But Davies rightly points out that this relationship is diminished slightly during outdoor running—on a treadmill, any tailwind that exceeds your running speed is wasted, as you must remain in place on the treadmill. However, results from real-world track races make it clear that, even in overground running, the benefits of a tailwind do not entirely offset the drawbacks of a headwind.

Davies also demonstrates that a tailwind that effectively eliminates air resistance (i.e. a tailwind equivalent to the speed at which you are running—so running at 6:00 mile pace with a 10mph tailwind) would increase your performance by about 6 seconds per mile, while the equivalent headwind (6-minute miles into a 10mph wind) would slow you by about 12 seconds per mile.


Davies also conducted some crude measurements of “drafting” behind other runners and found his data in agreement with Pugh: trailing another runner by a meter or so can remove up to 80% of the energy cost of air resistance, making it a very attractive decision on a windy day. According to Davies, a mile (on a day with no wind) tucked behind another runner is four seconds easier than running it alone!

Wind and heat removal
One final consideration when it comes to wind is its effect on heat removal from the body.

As pointed out in a 2012 review of climatic effects on marathon running by Greg Spellman, air resistance affects not only the forces you have to overcome, but your body’s rate of cooling.

While running with a tailwind certainly helps you move faster, the effect of running in “still air” on heat removal cannot be ignored. As far as I know, there has been little to no published research on this effect: to what extent does the increased heat retention in running with a tailwind detract from your running performance on a hot day?

And conversely, how much does increased cooling from a headwind offset the increased wind resistance?

Boston Marathon participants and organizers were ecstatic about the 15mph tailwind on a 63-degree day in 2011, which propelled hundreds of runners to personal records. But would participants in the 2007 Chicago Marathon, marred not only by 88-degree weather but a paltry 6 mph windspeed, have run better with a brisk wind to cool them? We’ll have to wait on future research to answer that question.

Numbers you can use to measure the affect of wind in your training
We’ve seen how the basics of the effects of air resistance have been known to exercise physiologists for some time. The performance hit from air resistance increases exponentially with faster running speeds and wind velocities, but fortunately, up to 80% of the performance decrement can be eliminated by drafting about a meter behind another runner.

Additionally, using a very rough rule of thumb you can anticipate the effect of wind resistance in a road race:

A “substantial” wind (i.e. one approximately equal to the pace you are running at) will set you back 12 seconds per mile with a headwind, and aid you by 6 seconds per mile with a tailwind.

Headwinds aren’t always your enemy, however, since a brisk wind can aid cooling on a hot day.

When it comes to choosing where you want to race, keep these factors in mind.

Finally, make sure you take advantage of a tailwind when you’ve got one!


References

1. Pugh, L. G. C. E., The influence of wind resistance in running and walking and the mechanical efficiency of work against horizontal or vertical forces. Journal of Physiology 1971, (213), 255-276.
2. Davies, C. T. M., Effects of wind assistance and resistance on the forward motion of a runner. Journal of Applied Physiology 1980, 48 (4), 702-709.
3. Spellman, G., Marathon running—an all-weather sport? Weather 2012, 51 (4), 118-125.

shortstuff!

Big Logger wrote: »

Or alternatively run behind someone who has more meat on them than you!

This might be the one time being petite comes in very handy:D

shortstuff!

PauloMN wrote: »

Oh by the way, for any of the 4:30/4:40ish boardsies, I'll be in red and white striped jersey and black shorts, say hi if you are close by! I'm the one with the flowing locks (NOT!).

I'll be the short one with a white t-shirt with Boards DCM Novice on the back so say hi!

donnacha

To everyone thats contributed to this thread over the past 6 months I want to say a really big thanks. To all that are running I really do hope you enjoy the day and achieve whatever goal you have set yourself. I'll especially be thinking of those that have had to pull out for injuries etc -I feel very fortunate that my blip came late August and I know I'm lucky to get the opportunity to give it a shot tomorrow - I'll be thinking of those that trained but had to pull out when the wall comes tomorrow.

Finally when the going gets tough I'll be repeating in my head something a friend posted on my charity page: "Pain is weakness leaving your body"

RedRunner

Best of luck everyone. Been following this thread with great interest all year.
I'm one of those unfortunate to have to pull out in the last week due to injury.
Savour every minute and enjoy!

snailsong

Ososlo wrote: »

what a lovely lovely thing to say. This means more to me than you'll ever know;) Surprised that anyone remembers that message from last year. It was my first ever post on boards almost a year ago. You might also remember then that I wanted to go sub 4 for my first, and boy did I work hard (hate calling it work as it's not really but you know what i mean!) trying to achieve that, I truly did, but I'm just not there yet. Somehow that doesn't matter so much to me this morning. I've had a blast trying and I'll have a blast trying again:) This really is just the beginning.
Cheers mate

You'll see tomorrow what a great difference the supporters and spectators make. It's what really sets this event apart.

You'll have plenty of time for sub 4 and better, enjoy tomorrow.

Just heading off towards Dublin ourselves now, wife driving. Really looking forward to it.

beertons

Best of luck to everyone tomorrow. I'm not running it myself but have been following it for ages. I am envious of all of you.

Ososlo

RedRunner wrote: »

Best of luck everyone. Been following this thread with great interest all year.
I'm one of those unfortunate to have to pull out in the last week due to injury.
Savour every minute and enjoy!

and well done you getting out there stewarding! I hope you get placed in a nice spot and the conditions aren't too bad. Good luck with it. I was out supporting for 4 and a half hours last year and didn't get bored once. Had to be dragged away. Hope you enjoy it.
You've been a great (virtual) support to me over the year. Thanks and you never know, I might see you in the pub afterward. Gonna play that one by ear...

rob w

Motivation Time....

https://www.youtube.com/watch?v=SuPLxQD4akQ&feature=youtube_gdata_player

chinguetti

Folks, best of luck to ye all tomorrow. For those who's its their first time doing the 26.4 miles (check your garmins afterwards), you'll learn so much. The nerves and nuttiness will soon be over.

Have a plan and stick to it. Don't bother about the weather whatever it is, you can do nothing about it. All you can do is rely on your training and yourself. Talking to yourself is normal. All the pain, the miles of running, the sweat will be worth it when you pass Trinity and take the final turn along Nassau St.

Don't give up, don't despair, don't set off too fast, don't take any of this on board if you wish. Some of you sadly will have a bad day but remember, we've all been there and its how you come out of it is the difference.

Be good folks, i'll be stewarding on the route. And remember, pain is your friend and there's no hills on route, just little bumps in the road.

ultraman1

best of luck tommorow folks.mite of been said b4 but you only have 1 first marathon,enjoy it...,(4:30 group is were its at:cool:)

PDCAT

Best of luck to everyone here tomorrow. You'll only run your first marathon once.... make sure and enjoy the day, the atmosphere is great in Dublin.
Hope you all get the times your looking for, but as it's the first one for all, make sure you take it all in.

In a little over 24 hours, you'll all be marathon runners - something that can never be taken away from you.

i look forward to reading the reports.

Laois_Man

Funny thought came over.....on this date, at this time, next year, I'll be somewhere around finishing my first marathon (hopefully).

imknackered

Best of luck tomorrow everyone, i was one of the late ones getting involved on this thread (mostly as i only decided to do the marathon in august) but i have found the information and chat on the thread really useful and really motivating.

Its my second marathon and all i can say to the first timers is (echoing the other posts) really enjoy the atmosphere around the course, makes all the hard work and hard miles worth it.

Good look making your goal times make sure to have more than one though as a fall back goal can keep you going if you fall off your original goal (speaking from personal experience in 2011!!)

Look forward to hearing everyones stories on Monday evening or Tuesday

ooter

This time last year I wasn't running a step and hadn't done so for almost a year because of injury,to be honest the pain was so bad I never thought I'd run again.I remember walking through the phoenix park the morning of the rearranged new York marathon,half of me was thinking those people were mad for putting themselves through that but the other half was so jealous because I'd probably never be able to experience that.
Got the all clear from the Hosp last December and started my first tentative steps back into the world of running.10 months later and here I am,on the eve of my first ever marathon and I just cannot wait for it,going to (hopefully) enjoy every minute of it.
Thanks to everyone who has contributed to this thread and offered their pearls of wisdom,especially career move,much appreciated.
Best wishes to everyone taking part tomorrow but especially to those who are doing it for the first time.

budgemook

I just read some people's dreams there and thought i'd share mine.

A few nights ago I dreamt that I started the marathon but went the wrong direction. I ran the full distance in a great time but realised it counted for nothing because I had gone the whole way in the opposite direction.

Was a weird one!

AlsoRan

rob w wrote: »

Motivation Time....

https://www.youtube.com/watch?v=SuPLxQD4akQ&feature=youtube_gdata_player

Absolutely loved this Rob, just the sort of kick we all need to get us going, I'll be using this as a mantra to get me around tomorrow. I haven't been posting much in the last few weeks as taper madness has been making me nervous as hell and really doubting myself. Everyone has been commenting on the demented look I get on my face when the DCM is mentioned. I'm looking forward to tomorrow but so scared as well :eek:

Best of luck to everyone, we've all done the work, let's hope the weather is kind to us and that we come out smiling on the other end!

Dow99

Ok its time for me to watch Spirit of the Marathon - If you haven't watched it I'd recommend putting the feet up for the next 1.5hr and enjoy!!

You'll be raring to get going!!!!

It's an award winning documentary following a group of people of all different abilities as they prepare for the Chicago Marathon.

http://www.youtube.com/watch?v=-7jNLVszR2A

Brian Purcell

Tomorrow will be great whatever time anyone does. Just remember to arrive in plenty of time to drop your bags, use the toilet, and get into your wave. There's no worse feeling in the world than panicking thinking you're going to be late, it also stresses you out for the first couple of miles too!

budgemook

Anyone know how traffic is today in ballsbridge? Might head back to the expo if it's not bad.

career_move

Dow99 wrote: »

Are people taking their own drink, whether it be a sports drink or just water on the route, or is there no real need as the water stations are sufficient?

I will be taking gels regardless.

Just take a small bottle/200ml with you in case you need a sip of water before the start and so you can avoid the first water station at 3 miles. You can just use the water stations after that.

Do not be sipping continuously from the bottle before the start for something to do/because you're nervous or you'll need to pee after a few miles

career_move

menoscemo wrote: »

Looks like the worst of the weather predictions are now behind us but there will likely be a decent/strong westerly breeze. If that's the case miles 2-6 and miles 11-14 (including the drag up crumlin rd) will be into the wind. Miles 14-20 (the flattest/ fastest part of the course) will be downwind.

So the message more than ever is to take the first 20m easy and push on from there. A pace group really could be the place to be tomorrow especially for the 'into the wind parts' in the first half. I would tend to tuck in even if the pace group is a touch too slow for your target. The amount of energy you save could far outweigh the few minutes you might gain pushing into the wind on your own. The second half should give you ample opportunity to pick up any time lost.

The word according to Meno

menoscemo

career_move wrote: »

The word according to Meno

Hey; you doctored my quote there

KillianByrne

Congratulations on getting this far folks, you've all made massive strides towards your goal and all you need to do now is trust your training. Start slow, find a pacer to hide behind and enjoy yourselves. I'm doing a virtual three cheers for C_M, she's done a sterling job and you're all ready for whats ahead of you.

Before you leave the house/hotel tomorrow morning though, say thanks to your partner or family, they're your greatest supporters and will be as proud of you as you should be of yourselves.

jonnner

Last question's before tomorrow!
I got a race number for wearing and another which is on laminated card, is that to go on your bag?
If I want to wear an extra top for the first few miles does it have to be under my t-shirt so my number can be seen?

Ososlo

jonnner wrote: »

Last question's before tomorrow!
I got a race number for wearing and another which is on laminated card, is that to go on your bag?
If I want to wear an extra top for the first few miles does it have to be under my t-shirt so my number can be seen?

yes the other number is for the bag you were given yesterday which you will hand in tomorrow morning.
It was said on another thread that it doesn't matter if your number is not visible as you cross the start line. It only matters when you go over finishing line.

BarneyJ

jonnner wrote: »

Last question's before tomorrow!
I got a race number for wearing and another which is on laminated card, is that to go on your bag?
If I want to wear an extra top for the first few miles does it have to be under my t-shirt so my number can be seen?

Ya the smaller number is for your bag. There is a space on the white plastic bag you got at the expo to stick it on. Though I presume you can use any bag you want. Your race number doesn't need to be visible at the start but must be visible at the end of the race.

Ososlo

BarneyJ wrote: »

Ya the smaller number is for your bag. There is a space on the white plastic bag you got at the expo to stick it on. Though I presume you can use any bag you want. Your race number doesn't need to be visible at the start but must be visible at the end of the race.

from the official DCM Instruction booklet :

"only baggage in the official Airticity Dub Marathon Bag, with the official baggage label firmly attached, will be accepted up to 30 minutes before race start." not sure how strict this is but just to be sure...

RunningKing

Ososlo - irregardless of what happens on the race tomorrow, you've done a Trojan job here with the novices.

Take a bow along with CM & Meno.

career_move

menoscemo wrote: »

Hey; you doctored my quote there

Same difference .... 20m is the real halfway