When a race course is certified by the RRCA or USATF, it’s measured by the shortest route a person can run and remain on the course.
When most people race, they run the most convenient route through the course that they can, which isn’t necessarily the shortest. Ignoring the inherent inaccuracies of handheld GPS devices, you might actually run as far as 27 miles during a marathon as the mile markers come further and further past where your watch tells you it should be.
If you want to run a faster time, it only makes sense that you should try to race along the shortest route possible. The way that you do that is to run the tangents.
What is a tangent?
Per Wikipedia: In geometry, the tangent line to a curve at a given point is the straight line that “just touches” the curve at that point. As it passes through the point of tangency, the tangent line is “going in the same direction” as the curve, and in this sense it is the best straight-line approximation to the curve at that point.
What this means is rather than following the curve of a road or your race course, you should aim yourself directly for the next curve that comes into sight and to only run along the curve when you can not see that next curve until after you’ve gone around the current one.
During training, it is appropriate and safer to run along one edge of the road as that will help you avoid getting hit by a car.
During a race, however, you want to run as straight a line as possible from one curve or turn to the next. You will cover the same distance (by road) in less time because you won’t have to travel as far (in actual distance.)
You may realize that on any given set of turns, running the tangent isn’t that much shorter than following the edge of the course. However, over the full distance of a race, especially one with a lot of turns and curves, it can really add up.
Don’t take this to mean that you should run the tangents blindly, however.
If there are potholes or other obstacles at the edge of the road, you may want to go around even if it means running a little further.
In a crowded race, you may not be able to run the tangents in the press of all of the other runners. Even if there are only 1 or 2 people around you, you still need to watch out that you don’t run into somebody or cut them off and cause them to run into you.
Also, you must be sure to pay attention to course markings and pre-race instructions. Even if a road has a turn, the course itself may not allow you to cross the yellow line in a road, for example.
And as always, defer to traffic, whether it is supposed to be allowed on the course or not. If you cross the road in front of a vehicle and it hits you, then a car will almost always win and a bicycle will usually win. Most vehicles are far less maneuverable as you are and you stand to lose more, so it’s always on the runner to avoid getting hit.
Try this simple strategy the next time you race. You can shave seconds off of a shorter race or even minutes in a longer race, which will help you reach the finish line faster in the exact same effort.