When you get the energy, perhaps an analysis of where improvements look possible for Asafa.
I heard a radio grab with him saying he was in trouble with his coach because he ran too tight in the last 30m, yet his velocity in the last 10m segment is still highly impressive - especially as compared with Tim’s last 10m segment. My maths is so terrible so I’m not even going to attempt to figure out if Asafa topped 12m/sec at any stage. Can you offer information there. Because if he did not top 12m/sec, then it is an interesting velocity graph which is almost level from 40m to 100m. His maintainance from 40 to 100 is phenomenal and to my mind suggests that perhaps he did not attain his potential maximum velocity in this race. I’m not saying this is a bad thing. It may in fact be a very desirable thing. The idea being that rather than hit the “ceiling” and “bounce” downwards, you skim just beneath the “ceiling” and stay at that elevation through to the finish line.
Good observation KK. Would it be possible for someone (PJ ) to look at some of his recent 9.8 races and see if he reaches 12m/s and then tails off (that is if he even reaches 12m/s).
0.84 section is actually 11.90m/sec. He has never reached 0.83 (although it was impossible to work on the Prefontaine wind-aided race since there was no visible mark on the track).
his speed maintenance is perfect. 1.70 in the last 20m matches Carl Lewis in Stuttgart’93 semis but it was a 10.02 race…
It can be compared with Griffith-Joyner in 88.
My opinion is that improvement won’t come from top speed, as 12m/sec has been reached or approached for a long time now. Same on the female side. Major improvement came from start/accel and speed endurance in sprint history. Seeing that Asafa is perfect (or close to) maxspeed/speed maintenance, improvement are now on start/accel phased. 6.39 is still short compared to Ben’s 6.33 in Seoul, and Tim, or Surin have run faster than 6.39.
Not wanting to give advices to Stephen Francis :o and i’ve really not interest in that either but the main flaw is in the transition between accel and max speed (where Asafa ups the head). You can see that something happens in the stride frequency/length curves in the 30-50m section. However this transition was much better than in Ostrava where he kept his head down for a too long time. His whole body was in place for several steps, but head position disturbed thebody control, he lost time there.
I am not a Powell fan, but his race was fantastic and I give him his full due for such a great performance.
His last 40m & 50m were the Fastest ever seen with 3.38 (0.02 faster than (official split) Lewis’ 3.40 from his 9.86 Tokyo’91. From my Video-Analysis I got Greene at 3.39 for his last 40m from his 9.79 Athens’99) and 4.23 (0.05 faster than (official splits) Lewis’ 4.25 from his 9.86 Tokyo’91 & Greene’s 4.25 from his 9.80 Sevilla’99. From my Video-Analysis I got Greene at 4.22 from his 9.79 Athens’99)
The difference in Reaction Times between Montgomery & Powell (0.104 compared to 0.150, 0.046 difference) shows Powell’s class
I haven’t been able to watch the race that closely, but from what I see is Powell cuts his stride off after he hits Max Velocity.
I think his SL could be a little longer.
A little phtosequence at 50 fps (picture every 0.02sec), showing take off extension, that’s his 35th steps, after 70m point (still running at 11.90m/s).
Comments anyone?
Kenny,
your right. That is what we discussed last time and we actually thought frames were missing. He did break the WR however so I dunno, how bad can it be? Anyone else care to comment, can he run faster with full extension or would that lengthen his stride and cut down the freq. what gives?
PierreJean,
Good analysis. I too have Dartfish. How do you view it at 50fps? It is set at 30fps correct? When making a photosequence I’m assuming you can set it to take the phots at any intervals but how do you change fps?
actually for photosequence i do not use dartfish, i use photoshop, again it’s way longer but it give better results… Kenny, the slow motion was at 50HZ, we will never know what AP does between 5th and 6th picture, maybe he’s fully extended… He does longer strides than last year btw.
If full extension does occur, it should be easy to find frames from the race that show this (to a much higher degree than the photosequence in question).
I don’t know how you change fps in dartfish but I have used SiliconCoach in the past and they allow you to effectivly double the number of fps because each frame is can be split in 2. I can’t remember off the top of my head how this works (i think it is something to do with the scan lines) but at the european 25fps this would make 50! Maybe you can do a similar thing with NTSC?
FYI : duplicated the following from an article on 4July2005 written by IAAF staffer for the IAAF website. . .
"A technical insight to Powell and Gatlin
But how do these two sprint stars compare technically? Here is the analyisis of the fastest wind legal career races of both Powell and Gatlin.
Powell is 1.88m tall and his weight is 87 kg. During his 9.77 second World record race in Athens he made 45.4 strides which means an average frequency of 4.64 Hertz. The wind was + 1.6 and his R.T. (Reaction time) was 0.150 seconds.
If you compare it with the legendary Carl Lewis, who has a similar body mass you will see a big difference because when Lewis ran 9.92 at the Seoul Olympic Games in 1988, he made 43.7 strides which means a frequency of 4.4 Hertz.
These athletes are/were using a traditional stride pattern while Tim Montgomery, the former holder of the World record mark, used a very abnormal stride pattern for a man. During his 9.78 he made 49 strides which means a frequency of 5.01 Hertz.
Justin Gatlin is 1.85m tall and weighs 79kg. He is at the opposite extreme to Montgomery. During Gatlin’s Olympic 9.85 second win in Athens, he made 42.2 strides with a frequency of 4.28 Hertz. The R.T. of Gatlin was 0.188 seconds, and the wind was +0.6."
Charlie, PJ perhaps, your thoughts??
The lessons?
(Maybe the lesson is that a good coach works with the individual before him and can find more than one way to reach the pinnacle of performance)
) to look at some of his recent 9.8 races and see if he reaches 12m/s and then tails off (that is if he even reaches 12m/s).
but the main flaw is in the transition between accel and max speed (where Asafa ups the head). You can see that something happens in the stride frequency/length curves in the 30-50m section. However this transition was much better than in Ostrava where he kept his head down for a too long time. His whole body was in place for several steps, but head position disturbed thebody control, he lost time there.