Originally posted by THEONE
Would’nt an analysis of Dwain’s stride length and stride frequency be needed to really see what is possiple with him.
To hit a 0.82 ten meter split I would guess a SF of over 5.? would be need or a SL of about 9 feet. Which one is his strength, and can it be improved.
re-stride analysis for Chambers 9.87 in Paris (see methods in my earlier post; stride frequency is searched from the time at each step; stride length is searched from the product of st. frequency and speed, and checked from the number of strides between the marks on the track…)
Distance / time for 10m section / stride length (m) / stride frequency (HZ)
RT 0.140
00-010m 1.75 / 1.41 / 4.09
10-020m 1.03 / 1.97 / 4.92
20-030m 0.92 / 2.19 / 4.96
30-040m 0.88 / 2.32 / 4.89
40-050m 0.85 / 2.36 / 4.97
50-060m 0.84 / 2.46 / 4.84
60-070m 0.85 / 2.44 / 4.83
70-080m 0.85 / 2.47 / 4.75
80-090m 0.87 / 2.45 / 4.69
90-100m 0.89 / 2.71 / 4.15
To compare, i’ve choosed to give results from JAAF biomechanical team for Tokyo’91 and Carl Lewis fomer WR 9.86. 9.86 and 9.87 are close times, but the race patterns are different.
RT 0.140
00-010m 1.74 / 1.39 / 4.13
10-020m 1.08 / 1.92 / 4.81
20-030m 0.92 / 2.44 / 4.45
30-040m 0.89 / 2.55 / 4.41
40-050m 0.84 / 2.56 / 4.66
50-060m 0.85 / 2.42 / 4.86
60-070m 0.84 / 2.50 / 4.76
70-080m 0.83 / 2.71 / 4.45
80-090m 0.87 / 2.65 / 4.34
90-100m 0.86 / 2.57 / 4.53
I use to divide 100m race in different parts, from the various time and stride analysis I’ve red.
10m + 30m + 30m + 30m = 100m.
Briefly, those are:
First section (0-10m) includes Reaction Time and start.
Second section (10-40m) includes acceleration. After the 40m point, usually stride frequency reach its maximum value and then decrease while stride length is still increasing (they usually don’t reach their max value in the mean time)
Third section (40-70m) is where sprinters reach their max speed. If they reach it before or after, there’s a mistake in energy distribution.
Last part (70-100m) is where they reach max stride length, which is often bigger in the last 10m as sprinter loose there body control and their stride frequency for various reason (stopping effort before finish line, rushing on the line, fatigue, bad concentration, etc). That’s the speed maintenance phase.
0-10m: with or without RT, Chambers and Lewis have nearly the same times, but even if stride length and frequency are similar, Lewis had longer legs than Chambers, and also will reach longer strides, so we can say that in this part, Lewis is focusing on smooth ground contacts and stride frequency (opposite as he did in Rome or Seoul).
0-30m: The aim of Lewis was apparently to have high cadence in his first stride in order to put long strides on his former frequency. The result is that he reach too long strides too early, while Chambers is more steady and is faster here.
30-70m: after those little troubles, Lewis is still searching a balance between his stride length and frequency, between pushing hard on the track and having the shortest time possible on the ground, searching the feeling of speed (note that we was clearly behind the leaders at this point of the race). Chambers curves are “normal”, nothing special to say here.
70-100m: back to Lewis: as a result of this, he reach is max speed very late, finally finding easy on his technique and seeing the others are decelerating. Chambers on the other hand looses his concentration, we can notice it from his strong decrease in frequency, resulting in a longer stride average in the last 10m. From the photofinish, we see that he was close to run in 9.86 (his 9.87 was rounded-up from around 9.867), and I think he could have run 9.85 if he had maintain his effort until the line.
But we’re far from 9.65!
Let’s see Chambers’ progression between Sevilla WCh’99 (from Spanish CSD Laboratory of Biomechanics) where he set his pre-2002 best and Paris’02
SEVILLA 22.08.1999
Wind Speed +0.2m/s
Temperature 30°C
Humidity 34%
PARIS 14.09.2002
Wind Speed +2.0m/s
Temperature 22°C
Humidity 53%
RT 0.140 both
010m 1.87 (1.73) / 1.89 (1.75)
020m 2.89 (1.02) / 2.92 (1.03)
030m 3.81 (0.92) / 3.84 (0.92)
040m 4.71 (0.90) / 4.72 (0.88)
050m 5.57 (0.86) / 5.57 (0.85)
060m 6.42 (0.85) / 6.41 (0.84)
070m 7.29 (0.87) / 7.26 (0.85)
080m 8.18 (0.89) / 8.11 (0.85)
090m 9.07 (0.89) / 8.98 (0.87)
100m 9.97 (0.90) / 9.87 (0.89)
Weather condition where different of course, but here what I see from this:
Same Reaction Time, and it’s in accordance with the other RT I’ve seen for him.
We see that in Paris he wasn’t as good as in 1999, but that’s probably because in Sevilla he had his peak form, while Paris came at the end of the season, analysis of his other races in 2002 would tell us.
He reach his maximum velocity in the same section, but his acceleration his better.
He has improve clearly his speed maintenance, but difficult to evaluate the wind assistance here.
Reaction Time & start, and maximum velocity are his shortcomings. Speed maintenance now is good (he losses 0.05 between his best section and the last one, that’s good assuming he didn’t pushed his effort until the end). His strength is acceleration, there’s not as much room for improvement here as in the other parts of the race.
I try a plan for his splits if he wants to run 9.65, with improvements for each 10m sections from his Paris race:
RT 0.110 -0.03
1.81 (1.70) -0.05
2.82 (1.01) -0.02
3.72 (0.90) -0.02
4.59 (0.87) -0.01
5.44 (0.85) -0.00
6.27 (0.83) -0.01
7.10 (0.83) -0.02
7.94 (0.84) -0.01
8.79 (0.85) -0.02
9.65 (0.86) -0.03
I compared his stride patterns with Ben Johnson’s as they had nearly the same height and also stride length. It’s clear that Ben put more frequency (reaching just over 5 steps/sec) at the start and in the acceleration that Dwain (and a little shorter stride length), The key is probably here to improve the first part of the race.