1. How Fast Can Usain Bolt Run?
John D Barrow

2. World 100m record progression: men

3. Swimming Improvements are Vastly Greater
Men’s 400m run: 43.8 (1968) to (2011)
Men’s 100m swim: 52.2 (1968) to (2011)

4. 2010 Berlin World Championships 9.58 s
Bolt’s 100m Record-breaking Progression
2008 Beijing Olympics 9.68 s
2010 Berlin World Championships 9.58 s

5. Reaction Time less than +0.10 s = 100 millisecs
Final Time = Reaction Time + Run Time
Reaction Time less than s = 100 millisecs
Means a false start and
Disqualification
Penalty kick 80mph = 36 m/s 13 yd (off ground = 11.83m) t = d/v = 0.33sThe average is about 0.19 secs for responses to light and 0.16 secs for responses to sound, and for touch. There are variations with state of mind, fatigue, artificial stimulants, and age. Neurophysiologists suggest that about seconds are needs to hear the starting signal. Cricket, tennis and baseball about 0.4s
Reaction time s (before the gun!)

6. The ‘Gun’ is Not Good Enough
+ Starter’s position
Sound speed = 340 m/s
Inside lane hears the gun
(15 -5)/340 = 0.029s
earlier than outside lane 5m
15m
This really matters!
The straight 200m timekeeping problem
sound travel time was 1.7s.
Timekeepers reacted to the visual flash – not the sound

7. 1960 Olympic Champion (was very suspicious) The ‘Anticipator’
Time Waited Before Green Light vs. Average Reaction Time
1960 Olympic Champion
(was very suspicious)
Armin Hary reaction 0.04s !!
The ‘Anticipator’ he
was found guilty in 1980 of a 3.2 million
DM (Deutsche Mark) swindle and sentenced
to 3 years in jail.
Reaction times, by month:                                                                                                                      
Copyright HumanBenchmark.com

8. Berlin World Championships
Bolt = 9.58
Gay = 9.71
Powell = 9.84
Bailey = 9.93
Thompson = 9.93
Chambers = 10.00
Burns = 10.00
Patton = 10.34
Beijing Olympic final: Bolt’s
reaction time was 0.165s for his 9.69s total,
The other seven finalists reacted in
0.133, 0.134, 0.142, 0.145, 0.147,
0.165, and sec.
Only one was slower than Bolt.

9. Quickest possible reaction is supposed to be 100 ms
ON GENDER DIFFERENCES IN THE REACTION TIMES OF SPRINTERS AT THE 2008 BEIJING
OLYMPICS
David B. Lipps, James T. Eckner, James K. Richardson, Andrzej Galecki, and James A. Ashton-Miller
University of Michigan, Ann Arbor, MI, USA
Web: me.engin.umich.edu/brl
DB Lipps et al
425 athletes. Male mean 168 ms with ms 95% CL
Female mean 191 ms with ms 95% CL
Estimated absolute min for male 124 ms, for female 130 ms
Male sprinters made 25 false starts in Beijing -- only 4 by females

10. Should there be different false start criteria
for men and women??

11. False starting is not the Answer
Daegu

12. Improvement Tip Number 1
Improve reaction time to 0.12 s and
9.58 s record improves to 9.55 s
Improve reaction time to 0.10 s and
9.58 s record improves to 9.53 s

13. Wind Assistance

14. Streamlining and Effective Body Area

15. Air Drag Mass of tube of air swept in time t is   A’  V  t = ma
 Speed V
Area, A(Bolt)
Mass of tube of air swept in time t is   A’  V  t = ma
= air density
A’ = c  A(runner) is the ‘effective’ body area
c = drag factor
Drag force from still air = -maV /t = - c A V2
Drag force with wind speed W = - c A (V - W)2
Following wind is + and Headwind is –

16. Running around in the Wind
Drag force with wind speed W is  (V - W)2
Power needed = Force x velocity  (V - W)2 x V
Following wind is + and Headwind is –
Disadvantage of headwind and crosswind beats
the advantage of a tailwind of the same magnitude
KV(V+W)2
Wind speed W in this direction
Lap
of square
track
Runner runs at speed V in still air
KV(V2+W2)
KV (V2+W2)
Power per lap = 4KV(V2 + W2 ) 4KV3
KV(V-W)3
It’s always slower running laps in the wind
Windy 400m- 10,000m races will be slower

17. A Wind-assisted Marathon
“It felt like there was no wind”  V = W
Drag force with wind speed W is - c A (V - W)2
Current record is 2:03:38, set by Patrick Makau on 25 Sept. 2011
Haile Gebrselassie’s old world record was 2hr 3m 57s
Ennanuel Mutai – no reln won Londo marathon the day after
April 18th 2011 Geoffrey Mutai 2 hrs 3m 2s Boston marathon (Moses Mosop 4 s behind)
Downhill point-to-point courses can’t drop more than 42 m. Boston drops 139 m !
Winner’s average speed 5.7 m/s -- close to estimates of following wind on the course
 3% power saving
Equivalent to a still-air time of 2 hrs 6m 45s with the wind always at his back.
Bunched for first half so maybe only had benefit for second half (run in 61m 04s !!!)
This gives a corrected time of 2hr 4m 52s.

18. Allowing for wind assistance in the 100m sprint
M = 70 kg
 = 1.19 kg/m3
A = 1.8  0.3 m2
c  1
About 3% of effort is beating wind drag
T(W=0) = [1.03 – 0.03(1 – WT(W)/100)2]  T(W)

19. Improvement Tip Number 2
“It’s an ill wind …..”
Improvement Tip Number 2
Roughly 2 m/s of following wind reduces windless time by  0.1s
Bolt’s 9.58 s was set with W = 0.9 m/s
Improves to
9.49 s with faster reaction time
and a W = +2 m/s tailwind

20. The Women’s World Record
‘Flo-Jo’
10.49 s
??????
Florence Griffiths Joyner
was almost certainly wind-assisted!

21. A Case of Wind Gauge Failure ?
Wind gauge read 0.0 m/s in 1988 US Olympic trials semi-final
Neighbouring jumps were experiencing 4m/s tailwinds
and the next semi-final had 5 m/s tailwind
10.49s broke the record by 0.27s !!
Similar dramatic improvements by the others in the same race
‘Real’ record is 10.61s in the final with +0.9 m/s tailwind

22. High-Altitude Sprinting Improvement Tip Number 3
Each 1000m of altitude produces a reduction in air density
worth about 0.03s over sea level for 100m sprinters
Mexico City was worth about 0.07s
Many actual records were improved by 1.7% in Mexico City
Improvements were much greater than air density effect alone

23. The Velodrome
Heated air at track level
Means
Faster cycling

24. Air Density Falls with Temperature
Hot air rises !
Drag force from still air  air c A V2
Air Density Falls with Temperature
  (deg K)/T

25. Air Drag at Track Level in the London Velodrome
Drag Force  air × frontal area × V2
A new type of ‘wind-assisted’ performance
Worth 1.5 sec over 4K pursuit

26. Effortless Improvements for Bolt
Improve Reaction Time
Maximise legal wind assistance to 2 m/s
Race at high altitude (2250m)

27. ‘Effortless’ Improvements for Bolt
His 9.58 s becomes
Reaction time improvement
 9.55 s
Maximise legal tailwind
 9.49 s
Race at max ‘legal’
high altitude (1000m)
 9.46 s
9.43s at 2240m

28. Is Bolt The Fastest? Usain Bolt’s average 100m is 9.530s
Blake: 19.26s - reaction time 0.27s = Run time of 18.99s
Bolt: 19.19s – reaction time 0.13 = Run Time of 19.06s
Usain Bolt’s average 100m is 9.530s
Yohan Blake’s average 100m is 9.495

29. How Accurate should the Wind Readings Be?
2 m/s limit derives from accuracy of 1936 hand-timing = 0.1s
Records now kept to 0.01 s so need wind accuracy better than 0.2 s
Wind gauge is at 50m point and 1.22m above ground
and within 2m of the track
Unfortunately wind gauge accuracy is only  m/s
And wind speed varies with position
This is a major inconsistency with record criteria

30. N. Linthorne

31. +
Bolt +
In Daegu Bolt is off the scale – in the wrong sense!
Starts before the gun is fired!

32. The Running Endurance Equation
Men: V  d-0.109
Women: V  d-0.111

33. The Wheelchair Endurance Equation
Men: V  d-0.006
Women: V  d-0.021
No significant
fall-off in speed
with distance!