Also, this is why I never believe anyone's self-reported 100 speed.
I've heard tons of people claim they can run 11 for the 100. Their real time is a second or two slower due to one or more of the following:
- Using a running start instead of a standing start
- Running 100 yards instead of 100 meters (more common for older runners, when they ran the 440 yards instead of the 400 meters. But I have heard of people running down the football field and using that as their 100 time)
- Self timing or having a non-track person time them (means that there's no reaction time, and the stopwatch is often stopped early since the runner or timer anticipates the finish)
- Stopping the stopwatch when a runner's foot, hand, or any part of the body crosses the finish line, not when his torso crosses the line.
- Running with a massive tailwind
- Starting the stopwatch when the timer hears the gun, not when the timer sees the smoke.
- Measuring out 100 meters on the street using Google (this usually ends up being a slight downhill run and a meter short)
- Exaggeration/BS (it's really a 12.4, but I rounded down to the nearest second to get a 12. I've got to brag, so it's an 11.99 now, and if someone asks me, I'll say I ran 11. something)