I was looking at the Book of Rules for athletic competitions published by World Athletics. In the section for road running events, rule 31.21.2 says
The start and finish points of a course, measured along a theoretical straight line between
them, shall not be further apart than 50% of the race distance.
So, for example, a completely straight course is prohibited. What is the point of this? What difference does it make what the straight line distance is between the start and finish?
To reduce the likelihood of a tailwind for the entire course. Although I’m not sure why it would matter except for the validity of any record. Perhaps because some athletes are better than others in tailwind/headwind, so aside from the validity of any record, it would favor some athletes to have a constant headwind or constant tailwind? Other things being equal, more heavily built runners will be better in a headwind.
You can have a perfectly straight course. However, it will not be eligible for possible world records.
The idea is to cancel out a downhill and/or tailwind assisted time.
Ah, I never thought about a tailwind. Thanks, ignorance fought!
I think it’s more for elevation loss than tailwinds, but both are valid factors. For example, the Boston Marathon, being a point to point course and dropping 3.3 meters per kilometer, is not certified for any world records.
There’s a separate rule for elevation:
31.21.3 The overall decrease in elevation between the start and finish shall not exceed 1:1000, i.e. 1m per km (0.1%).
The link won’t open for me, but I assume there’s an exception for extremely short races like 100m.
These rules are for road races. Track races are required to have a certified wind gauge for record consideration. 2.0m/s and over disqualify a record. Straight line events only (100, 200, triple/long jump, 100/110 hurdles)
So are races like the Fifth Avenue Mile not eligable for any records?
It’s a road race so it has to meet the start/finish line separation requirements.