According to IAAF Analysis Split Times, Usain Bolt ran his first 40m in 4.65 seconds. Subtracting his reaction time which was .165 seconds, he ran the 40m in 4.485 seconds. 40 yards is a totally different measurement than 40 meters. 40 yards is equal to approximately 36.576m
By simple ratio:
(40m/4.485)=(36.576m/X)
X=( 36.576 / (40/4.485) )
Usain Bolt's 40 yard dash would be: A blazing 4.100 seconds! Considering the human error in hand-timed timing used in most combine settings, this time could easily be read as 3.85 seconds at the NFL Combine!
DIFFERING VIEWPOINTS:
There are several errors in this presentation.
I did research comparing the 40 meter times and 100 meter times of extremely fast football players, such as Trindon Holliday, Jeff Demps, Bob Hayes, Deion Sanders, and Herschel Walker. For every 40 yard split of each athlete's 100 meter time, the split was, on average, about .5 seconds faster than the athletes' actual 40 times. I found a common ratio of 40 time to 40 yard splits in the 100: the actual 40 was about 1.142 times longer than the 40 yard split time. record 100 meter time, and using the ratio, I calculated Usain Bolt's probable 40 time to be 4.003 seconds. I know it sounds ridiculous, but the math is correct. It is not an exact science, but it is a very good estimate.
However, don't forget that NFL players don't use "blocks" when doing the 40 as they do in track. They are more prone to "rising" faster out of their stance since they have to push off of the ground instead of the "blocks." Blocks will improve your time.
Usain Bolt's current 4o yard dash time is 3.97.
Usain bolt runs his 40 yard dash in around 4.2 seconds.
0.0004- just joking its 3.53
About 3.4 sec.
This belongs to Asafa, who has a superb start.
The 100y is rarely run outside the US, however, it is likely that Bolt will have passed the 100y mark in his best 100m race in around 8.75s.
11.37 . About 1 1/2 seconds slower than usain bolt
The fastest record speed attained by a human on foot is 27.44 miles per hour. This speed was attained by Usain Bolt in the 100 yard dash.
Usain Bolt was clocked at 3.9 sec in the 40 yard dash at a sports complex in Florida. That's faster than what it takes to read these sentences!
Mathematically calculated Rose' 40 yard time is 4.48.This was calculated by taken Chris Johnson's 20 yard time and Derrick Rose' 20 yard time of 2.65 in which i got from http://www.muscleprodigy.com/derrick-rose-workout-arcl-1189.html and subtracting the two times and I accumulated 0.24 I added 0.24 to Chris Johnson's 40-yard time and that equaled 4.48.
Chris Johnson, he ran a 4.24 40 yard dash and DeSean Jackson ran a 4.35 40 yard dash.
Eli Manning's 40-yard dash time is 4.92.