How Fast Can Usain Bolt Run? John D Barrow http://www.google.co.uk/imgres?imgurl=http://allsportseverything.com/wp-content/uploads/2011/05/usain-bolt-olympics-200m.jpg&imgrefurl=http://allsportseverything.com/2011/05/todays-sports-tweet-usain-bolt-on-todays-race/&h=300&w=500&sz=45&tbnid=1XenqOY4DAeZ4M:&tbnh=73&tbnw=122&prev=/search%3Fq%3Dusain%2Bbolt%26tbm%3Disch%26tbo%3Du&zoom=1&q=usain+bolt&docid=JKXGc8jxGPgz3M&hl=en&sa=X&ei=Y8OvTtiyGZDKtAa-7Zxx&sqi=2&ved=0CEQQ9QEwAg&dur=5469

World 100m record progression: men

Swimming Improvements are Vastly Greater Men’s 400m run: 43.8 (1968) to 43.18 (2011) Men’s 100m swim: 52.2 (1968) to 46.91 (2011)

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

Reaction Time less than +0.10 s = 100 millisecs Final Time = Reaction Time + Run Time Reaction Time less than +0.10 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 0.155 for touch. There are variations with state of mind, fatigue, artificial stimulants, and age. Neurophysiologists suggest that about 0.08-0.10 seconds are needs to hear the starting signal. Cricket, tennis and baseball about 0.4s Reaction time -0.104 s (before the gun!)

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

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: 2006-12 231.7210  2007-01 230.2160  2007-02 221.5340  2007-03 213.5495  2007-04 218.2240  2007-05 223.5815  2007-06 227.9971  2007-07 218.9489  2007-08 223.1460  2007-09 225.2622  2007-10 225.6355  2007-11 226.1450  2007-12 225.0047  2008-01 224.1950  2008-02 228.6108  2008-03 225.5128  2008-04 224.1333  2008-05 221.8307  2008-06 223.8115  2008-07 220.1270  2008-08 223.6209  2008-09 228.1079  2008-10 225.6141  2008-11 225.1891  2008-12 225.3566  2009-01 229.3421  2009-02 227.8805  2009-03 227.0507  2009-04 227.6157  2009-05 226.7158  2009-06 218.5118  2009-07 219.2302  2009-08 225.1163  2009-09 225.8613  2009-10 227.8240  2009-11 228.3662  2009-12 227.8109  2010-01 233.3751  2010-02 232.7230  2010-03 238.8148  2010-04 233.1478  2010-05 233.6491  2010-06 230.2473  2010-07 241.0561  2010-08 239.1098  2010-09 240.2925  2010-10 242.6746  2010-11 243.6936  2010-12 240.3398  2011-01 241.4032  2011-02 246.1841  2011-03 248.7490  2011-04 244.2065  2011-05 247.0543  2011-06 246.5999  2011-07 241.3142  2011-08 245.9536  2011-09 252.5752  2011-10 251.1309  Copyright 2006-2010 HumanBenchmark.com

Berlin World Championships Bolt 0.146 + 9.434 = 9.58 Gay 0.144 + 9.566 = 9.71 Powell 0.134 + 9.706 = 9.84 Bailey 0.129 + 9.801 = 9.93 Thompson 0.119 + 9.811 = 9.93 Chambers 0.123 + 9.877 = 10.00 Burns 0.165 + 9.835 = 10.00 Patton 0.149 +10.191 = 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 0.169 sec. Only one was slower than Bolt.

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 email: dlipps@umich.edu, Web: me.engin.umich.edu/brl DB Lipps et al 425 athletes. Male mean 168 ms with 160-178ms 95% CL Female mean 191 ms with 180-205 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

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

False starting is not the Answer Daegu

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

Wind Assistance

Streamlining and Effective Body Area

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 –

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

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.

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)

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

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

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

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

The Velodrome Heated air at track level Means Faster cycling

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

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

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

‘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

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

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  0.2-0.5 m/s And wind speed varies with position This is a major inconsistency with record criteria

N. Linthorne

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

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

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