Tangents

[Carolyn Herlin]

I read advice in another thread to run tangents. As a newbie, I don't know what that means. Can someone explain?

Thanks,
Carolyn

[Paul Petersen]

It's a very important concept. Courses are measured using the shortest possible distance. See articles below for explanations and diagrams:

http://www.runninginjuryfree.org/tangents.html
http://www.runningonline.com/zine/Race_Day/117.sht

[Carolyn Herlin]

Makes sense. Thanks!

[Scott Zincone]

In regards to the article on the second link Paul gave, when watching the U.S. Trials a couple of months ago I wondered about the 800 runners.  They seemed to immediately cut over instead of doing it gradually.  They are the best we got, so how come they run such bad tangents ?

[Jon Allen]

It's not all about distance on the track, since the difference is at most a few meters for their tangent.  In track, there is a lot of positioning in the group.  You don't want to be on the outside and have to run the race in lane 2 or 3.  So one bad tangent is better than being stuck in an outside lane for a couple of turns. 

[Scott Zincone]

Good explanation.

[adam]

That's true for the 1500m as well, and other races towards the finish (where swinging wide can give you clear track).

Practice learning tangents on your runs. Learn to visualize them so when you race you can spot them right away.

[Sasha Pachev]

Doing your tangents right is much more important on a windy road than on the track (off the curve) or meandering through a rectangular city block. Assume the road width is 20 meters. If you just turned right on it, and then have an very long straight stretch (lets say 2 miles long) and then have to take a left, the difference between the best and the worst tangent in cutting across is 20 meters. If you cut across over only a 20 meter stretch, you lose only 6 meters. If you aim better and do it over 100 meters, you lose less than 2 meters compared to the perfect aim. The shorter the length of that stretch, the less you lose by a bad aim. However, if you end up taking the corner wide on a 90 degree turn you lose about 1.57 (more precisely PI/2) times the distance between where you are and where you should have been. So for every meter of displacement you lose 1.57 meters of distance.

Now suppose you are on a 20 meter wide canyon road that makes a 90 degree turn. On a course like TOU you could have a turn like this that happens over a stretch as short as 0.2 miles. And you could have a lot of those. If you find yourself on the wrong side of the road and stay there for the entire turn you've just lost over 30 meters. 10 turns like that, and you've now lost over 300 meters. That is over a minute at 5:20 pace. That is why I always ask volunteers to come out to me if the water station happens to be on the wrong side of the road. I will often skip the station altogether if the volunteers do not come out.

[Paul (RivertonPaul)]

Thanks for the information on tangents.  What do you all do on those 90 degree corners that you could cut across the grass or pavement?  What is proper protocol?

[Paul Petersen]

Run behind Bill Cobler and just do what he does.

Seriously, stay off private property first of all. Beyond that, read the fine print in the rules or ask the race director what "out of bounds" are. Then cut every corner you legally can.

[Jon Allen]

One note, though- I have found it very difficult to hold a good tangent across a long straightaway (like Sasha's 2 mile stretch).  I tend to drift more quickly towards the next turn direction.  But I don't think this is too bad- you may lose a meter or two, but you expend less mental energy focusing on running an exact line.  Easier to just drift along the side of the road.  It is easier to run a good tangent for me on a short straight stretch than long.  A sloped road also often pushes me to either stay in the center or either edge, rather than run perfect tangents.

[Scott Zincone]

How about 180° turns ?

Some of routes take me thru cul-de-sacs.  I really hate making that type of turn.  Watching the Women's Olympic Trials this year the had the same type of turn many times.  What are some good tips on taking those.

Also in a race on a normal 2 lane road with a cone in the the middle where the turn around mark is.  Any tips for that as well ?

[Sasha Pachev]

On a 180 maintaining your speed is more important that cutting the distance. Taking them a little wider is a good idea. Just pretend you are in a high speed chase and have to make a U turn :-)

[Scott Zincone]

Speaking of tangents, they played a part in the USA Road 1 Mile Championships yesterday.  Especially in the men's race.  You can see and hear what they said about them in the videos.

http://www.usatf.org/events/2009/USA1MileRoadChampionships/video/