Every time we see a Usain Bolt powering past his
rivals after 50 or 60 metres in a 100m sprint, many of us might have marveled at
the speed that the Jamaican generates through those final metres.
“With a tremendous burst of speed the young sprinter raced
past his rivals after 70 metres to re-write the 100m record”. I grew up in the
profession reading such descriptions of the 100 metres.
Sprinters tend to hit top speed at the half-way mark
in a 100 metres or by around 60 metres or just after that. Beyond 65 metres or
70 metres even the great Usain Bolt starts slowing down. There is no extra
burst of speed that he can produce to outsprint the others through those
agonizing 20 or 30 metres though he looks to be moving at a greater speed than
through the preceding 30 metres.
Simply put, Bolt is decelerating slower than the
others. It looks the winning sprinter has just shifted gears after 60 or 65
metres and lo and behold he just bursts through the final 35 or 40 metres!
The different phases of sprinting have been researched
by bio-mechanics experts and physicists through decades and they came to this
conclusion, explained in great detail in many an article. (Research is still going on to find out exactly what contributes to speed.)
Thus, it has been interesting to read many reports
post-Rio Olympics (some before the Games, too) about Dutee Chand slowing down
after 60 metres and being unable to chase down her opponents through the last
40 metres.
Dutee can of course work on her speed endurance which
will make her deceleration over final 40 metres or 35 metres slower than what
it is today. It will not mean she will be faster through that stretch compared
to her preceding 30 or 35 metres but she may not be left too far behind.
(Speed
endurance is something which national record holder in 800m, Tintu Luka, also
needs to build up in order to succeed at the highest levels. Every time she
takes the field through an opening lap of 57.8s and then fails to match the
rest through the final 200 or 150 metres there is an outcry to belittle the
Kerala woman’s effort and that of her coach P. T. Usha. Both know what they
have to do. It is easy to say “Tintu needs to build up her speed endurance” and
a lot different for the athlete herself to come up to a level to beat the best
in the world).
Back to sprinting. The best of the sprinters either
decelerate slower than the others or else are able to maintain a high level of
speed through the last 30-40 metres almost matching, but rarely exceeding, any of
the previous 10 or 20-metre segments once past 40 or 50 metres. Surely once a sprinter hits top speed there is a limit to the distance he/she can maintain that speed.
Slightly deviating from the theory of slowing down at the finish, both Carl Lewis
and Leroy Burrell of the US, turned in faster efforts through the last 10
metres than between 80 and 90 in the famous duel in the 1991 World
championships in Tokyo which produced a world record for Lewis at 9.86s.
Burrell who held the previous WR (9.90s) timed a personal best 9.88s for the second place.
Lewis ran the final 10 metres in 0.86s compared to the
preceding one in 0.87s while Burrell’s corresponding splits were 0.87s and
0.89s. In comparison, another American Dennis Mitchell, who came third, ran
0.90s and 0.87s respectively.
Lewis and Burrell were of course slower for the final
30 metres compared to the preceding 30 metres.
If Dutee Chand is getting beaten through the last 40 or 20 metres by better-rated, better-prepared sprinters and her coach feels she should be capable of putting up a better fight, if not win such races, it is her deceleration
rate that matters. But that is true of anyone who might be coming second, third
or fourth or down to eighth, notwithstanding of course the ‘start’ that also
plays an important role. It goes without saying that the one who decelerates
the least will eventually win provided he or she has the ability to hit a
speed that matches the rest.
Slowing down in last 40 metres
Dutee has illustrious company here, as explained
above, including the greatest of sprinters headed by Bolt. If not from 60
through to 100 metres at least from 70 to 100 metres.
But then we also have to keep in mind that the first
10 or 20 metres is not going to be too fast. The push off the blocks and the
initial momentum will take much more time than the stretch between 40 and 70
metres when sprinters would have hit peak speeds.
Usain Bolt reached a maximum speed of 12.27m/s
(44.172km/hour) in his world record 9.58s in the 100m at 65.03m in the Berlin
World Championships in 2009. According to a biomechanical analysis conducted by
the DLV (German Federation) Scientific Research Project, Bolt hit 99 per cent
(12.15m/s) of his maximal velocity at 48.18 metres.
Bolt covered his 10-metre segments in that historic,
stunning world record in: 1.89s, 0.99, 0.90, 0.86, 0.83, 0.82, 0.81, 0.82, 0.83
and 0.83. He had a reaction time of 0,146s, the fifth best in the eight-man field.
That means Bolt’s best average speed was recorded
between 60 and 70 metres (0.81s). In the next 10m he slows down a bit (0.82s) but
amazingly maintains 0.83 for the last two 10-metre segments.
Carl Lewis, in his Tokyo WR hit top average speed
between 70 and 80 metres (0.83s) and then timed 0.87 and 0.86s for the next two
10 metres, according to available statistical data.
It is difficult to imagine the newly-crowned Olympic
100m champion Elaine Thompson of Jamaica would have said that Dutee needed to
improve her “surge” from 60 to 80m and later from 80 to 100 metres to win
medals in higher level competitions, as explained by the latest Dronacharya
awardee coach, N. Ramesh in a recent report.
Poor start
The Jamaican who despite a 0.157s reaction time
(second poorest) in the 100m final in Rio clocked a 10.71s to take the gold
might have meant Dutee needed to work on her speed endurance so that she was able to
maintain better rhythm through the final stretch for a better finish. Trying to
work up extra pace through 60 to 80 or through 80 to 100 would not fit into the
scientific analysis established through many years of work by experts. It
defies logic too.
Incidentally, Dutee’s was also the second poorest
reaction time in her 100m heat (0.151s) when she timed 11.69s. The poorest was
by “preliminary qualifier” Patricia Taea of Congo at 0.159s. She clocked 12.41
to be placed eighth and last, a rung behind the Indian star.
Dutee blamed her poor performance (11.69s as against her national record of 11.24s in Almaty in June) to the late evening
start (11 p.m) which she explained was
her “sleeping time”.
(Updated Oct 5, 2016)
