Most people think the marathon 26.2 miles. This is true only if they run the shortest legal route possible. However, most people run much further. These runners will add enough extra distance to adversely affect their time. By learning to run the course properly, it is possible to knock anywhere from 3 to 5 minutes or more off your time. Each course is measured on its shortest possible route. The goal is to stay on that route line as much as possible. The only time you ever want to be off the route line is to get water, avoid traffic or run on a surface that is superior to the route line. On some hot days it may be better to run in the shade than to be on the Route line.
Using the New York City marathon as an example, there are 46 turns once people enter Central Park. If they are not running the tangents, they are adding at least 2 to 3 seconds per turn. This is over 2 minutes in just that section alone.
People tend to stay on or near the center line for the entire race. Even on a 90 degree turn where the inside curb was 30 feet away, they will stay on their line. Do not do this, this adds time! Over the course of a marathon, this distance certainly adds up.
Obviously many people figure it doesn't matter all that much. The math, however, will show different results. After the L.A. race, there were complaints on the bulletin boards, that the course was too long. Instead of the 26. 2 miles, some runners who brought their fancy high tech GPS had readings of 26.55-26.65. This meant these runners ran an extra 1/3 of a mile because they did not run the tangents. It is in my estimation that a bulk of the runners will run an extra 3-5 tenths of a mile over the course of a normal marathon. This means a runner who averages 10 minutes a mile will run an extra 3 minutes and 30 seconds to an extra 5 minutes because of the extra distance.
You do not want to be one of those runners who needlessly adds 5 mins to their time.
The goal is to picture your self like a race car driver that tries to take the inside line on every curve. This will save significant distances over a course of a race.
Here is a map that shows the first mile of the LA marathon. The course is measured from the exact inside line. The width of the road was about 80-100 feet wide. Running an average 60 feet from the inside line for the entire mile, would cause one to run an extra 376 feet. For a person running a ten minute mile, this shows they would run and extra 42 seconds just in the first mile.
This picture shows runners going up Temple Street in the L.A. marathon. At the bottom of the hill, the runners made a right turn onto this street. At the top of the hill, the runners made another right turn. This Street is about 80 feet wide. This means the people on the right of this picture ran an extra 160 feet just in those few short blocks. If they were running 10 minute mile pace, they added 18 seconds to their time. The ideal line is to stay as close to the right curb as possible.
With the above examples, it is easy to see how one could lose ten to twenty seconds here and there. These seconds soon add up to minutes.
The goal is to take the same line that the course is measured on. This requires focus on your part. Plot your heading after coming out of each corner.
Another step to take is to try and memorize as much as the course as possible. Most marathons have excellent course maps. I suggest driving the course if possible. If not possible, then visit Google Maps and use street view.
This will reduce a bit of time when the next corner is not visually apparent.
In the latter stages of the race, try to keep your head up after you come out of a turn to plot the new direction you will be heading. It is useful to find a reference point out in the distance to head towards.
Remember the analogy. You want to see your self as a race car driver trying to take the inside line on every turn.
For those that want to knock an addtional 2-3 minutes off your time go to this link where you will learn how to tie your shoes. (how to tie your shoes)