Why wasn't Boston course aided for the non-elites?

I agree. I ran Trail's End in Seaside, OR in 1980, a long, narrow loop, almost an out and back. Out was relatively sheltered from a tailwind, though in 2:47 ish shape,I hit the turnaround in 1:20. Then we turned back into the wind on exposed roads parallel to the beach. Headwinds were consistently 30mph, with gusts, the Weather Service reported, of up to 70.

By far the worst part was a little section at 21 miles that took us back North with the wind at our backs before turning around again. With stiff winds at my back, I was "forced" to run that mile in about 5:20, roughly 2-mile PR pace. Then, of course, it was another four miles against the wind to the finish. The headwind obviously drained almost everyone's glycogen tanks prematurely, and those forced to walk went hypothermic.

Kevin Galbraith, one of my students then, and Head T&F Coach at Northern Colorado, Was carrying my drinks. He was supposed to hand me one at 19 miles, when I emerged back onto the highway after a little loop that took us out to the headlands. He took a photo instead. Hopping on his bike immediately and pedalling for all he was worth, it took him about a mile to catch up to me, such are the forces of a headwind on a cyclist.

Malmo, I was being factitious, I know my physics. I'm with you here about the wind advantage, but I have to admit that as a scientist that I would be hesitant to place a time value on how much the leaders were helped. Even if I were to take the time to try to analyze all the variables involved with possible wind advantage on the Boston Marathon course (complete with Purdy pictures ....) placing a number on that advantage would be problematic.

BUT, this thread is not about the leaders who, regardless if someone was running behind them to insignificantly dampen the effect of the helping wind, received a major advantage. You know 99.9% about this sport, but I will venture to say you do not know what it's like to start with the 2:55 group at Boston. Off goes the gun, and you don't move. When you do move, you walk. Race pace? 15:00 into it. Hundreds of people ahead of you, hundreds of people behind you. SO MANY people behind you that it may .... just .... act .... like .... a .... Greyhound bus.

Here's a perspective from a mid-packer: I ran Boston this year; I started in the middle of the 2nd wave and was packed into that corral like a sardine. There was no danger of going out too fast; there were too many people in front of me to even attempt to pass. The congestion was insane. And as soon as we started running I was uncomfortably warm. At no point did I feel any wind whatsoever, other than a tiny cross wind heading into Boston. If anything, the heat was a detriment to my race and if it had been a cooler day I would've run at least 2-3 minutes faster. And if the last 10 miles had been flat I would've been even faster still LOL

Back to the original question, “why does the wind affect the elites more than the non elites?”

First let's isolate the effect of air resistance on runners. When you compete there are a lot of factors that determine how fast you can ultimately run. Obviously first and foremost is the energy that is required to move your body and to keep it in motion once you’re moving. To a much lesser extent is the additional energy requirements required to simply push your body through the resistance due to the density of air.

We can stipulate as fact that as the velocity increases the air resistance is proportional to the square of the velocity.

If you increase your speed by two units of velocity the air resistance increases by 2² or 4. Increase your V by 3u the resistance increases by a factor of 9. The inverse holds true as well. As you can see from this table the exponential relationship at work.

2 4

3 9

4 16

5 25

6 36

7 49

8 64

9 81

10 100

Here is a table of values of velocities for marathoners ranging from 2:03:00 to 4:00:00 compared to their relative air resistance in still air. I arbitrarily assigned the 4 hour marathoner’s velocity of 2.930 meters per second to be the base of “1”. As you can see a 14% increase in velocity to a 3:30 marathon results in a 31% increase in air resistance. A 60% increase in velocity to a 2:30 marathon results in a 156% increase in air resistance. A 2:03 marathon is 95% faster and has a 281% increase in air resistance.

Having a wind in your face a 2u velocity is just the same as running faster by 2u velocity, from the perspective of air resistance. It follows that having a tailwind reduces the air resistance in the same manner.

It should be obvious that any specific unit of tailwind is going to result in a disproportionate amount of reduction in drag at the higher velocities (of elites) compared to the same unit velocity reduction at the slower velocities (of non-elites). Just in case you aren’t convinced I’ve created a table to illustrate this.

(go to the top right corner of the message board and adjust your settings to “view images” so that you can see both the image and text)

You’ll notice that if you have just a 2.0 mps tailwind (the maximum allowable in a track meet) 4:00 marathoner will reduce his drag by 90%, a 2:30 marathoner will reduce his drag by 172% and a 2:03:00 marathoner will reduce the drag due to air by 220%.

Increase the wind speed to 2.93 mps the 4:00 marathoner reduces 100% of his air drag due to the fact he’s running exactly at the same speed as the wind. The 2:30 marathoner has now reduced his air drag by 220% and the 2:03 marathoner has reduced his drag by a whopping 290%.

These calculations are done with very low wind speeds. Now you can argue in circles whether or not the actual ground level wind speed is the same as what is recorded at an airport (of course it’s not). What you cannot argue is that the ground level wind speeds at the 2011 Boston Marathon were not significantly greater than the calculations I’ve just provided.

Elites do benefit more from a tail wind than non-elites, simply because of the logarithmic nature of the force of the air resistance.

Mass vs surface area

Highly trained marathon runners are significantly leaner than club recreational racers and hobbyjoggers. Yes, of course you will find some skinny freaks who run no better than 4:00 for the marathon, but, by and large, to a great degree if you see a group of very tiny, and very lean men at a marathon, they are most likely your elite runners.

Body mass is proportional to the cube of the radius of any unit of body volume, while surface area is proportional to the square of the radius of any unit of body volume. In other words the relationship of mass to surface area is greater in an untrained or undertrained runner than it is with the most extreme body types that make up the elites. An elite will compound his advantages due to higher speeds with the advantages of his lower mass relative to the surface area of his backside when he has an assisting wind at his back.

Physical conditioning

With any untrained runner the amount of lactate accumulating in the bloodstream increases as the speed increases. As you train, that curve will start to flatten out, then turn up at the inflection point called the OBLA point (Onset of Blood Lactate Accumulation). An elite athlete’s OBLA curve will shaped like a boomerang -- really flat and pushed WAY out to the right before it climbs. Any factor that will allow him to push that curve just a little bit more to the right will greatly affect his performance. Having a wind at his back, any wind at all, is more beneficial to him than the hobbyjoggers and recreational racers becasue of the nuances of the OBLA curve. Because of the flatter OBLA curve those elites will be able to maintain even higher velocities than normal, before the slope of lactate accumulation makes its turn upwards.

The elite's light weight relative to his surface area allows him to take advantage of the wind more than the hobbyjoggers and recreational racers. It also benefits him from a heat exchange perspective. All of these factors together will compound to give him a much lower energy cost advantage over the non-elite by a disproportionate magnitude, allowing him to explore the far right corner of that OBLA wilderness that the sub-elite, recreational racers, and hobbyjoggers could never imagine.

Competitive mindset

Elites, by their very nature are competitors first. They are not fitness runners. They live and breathe to race. They live for the day they can test themselves at the extreme edges of human performance. For the recreational racer or slogger, what they do isn't doesn't even remotely compare. For the sub-elite, let's say a 2:20 marathoner, what is going on at the front is a different ballgame altogether.

When elites get together in competition all hell breaks out. When sub-elites get together it's merely a robust competition. With the hobbyjoggers, it's woooo-weeee, look at me mom, I'm runnin the thon!

Syzygy

When you combine all of these factors together on a point-to-point course with the "Breath of God" at their backs you get Ryan Halls dreams:

"If we get a good day. Get a good tailwind. Cool day. Sky's the limit. When you are running one direction. You get a tailwind. You can really roll. I'm waiting for one of those years." - Ryan Hall, before the 2011 Boston Marathon

malmo wrote:

Elites do benefit more from a tail wind than non-elites, simply because of the logarithmic nature of the force of the air resistance.

Exponential nature.