The 2010 edition of the Tour de France is approaching its conclusion in Paris. The race for the yellow jersey, or winner of the Tour, has been an exciting one. Alberto Contador and Andy Schleck have been the stand out riders in the mountain stages. The two are seperated by a small margin of only 8 second, which Contador gained because of a mechanical failure at a critical moment for Schleck.
Stage 18 of the race should put the focus back onto the sprinters, at least those that made it through the mountain stages. The stage sprint winner will rely on skilled lead out riding from their team mates and powerful sprinting to gain the victory. The 2010 Tour has seen dangerous and sometimes illegal moves in the sprints. Mark Renshaw, of team HTC Columbia, was disqualified for head butting another sprinter (not once but three times) as he lead out and created a sprinting lane for his team mate Mark Cavendish.
The sprints seem so chaotic that we wonder how anyone can get through without some illegal moves. The video below describes the cycling rules for sprinting and shows some examples of what is allowed and what can and should lead to disqualification.
Two more sprints will be contested in the 2010 tour and we can look out for the way in which the sprinters and their lead out men ride their lanes and deviate from them to cut off opposing team riders.
Mark Cavendish is once again favored. With his speed and power he does not need his team mates to head butt other riders to get another win and without his lead out rider Renshaw, he will get his chance to show us.
We have previously stated here that we think Usain Bolt can lower the 100 meter world record.
We have suggested that he can start faster, train harder on his fitness and of course refrain from celebrating before crossing the line. All of which suggests that his 9.58 second 100 m and 19.19 second 200 m world records will be broken.
On Saturday the BBC aired a documentary on Usain Bolt "Usain Bolt: The Fastest Man Who Has Ever Lived". In this documentary Michael Johnson, the 400m world record holder and second fastest man over 200m (after Bolt) talks about the biomechanics of Bolts sprinting.
Johnson says of Bolt: "He has ... an incredibly long stride combined with the ability to execute a race like a shorter sprinter - generating the same explosive power. That combination makes him so much faster than the rest of the field."
But he suggests that slow motion video shows that bolt has lateral movement in his sprinting mechanics. In other words he moves his body side to side as he runs. This sideways movement reduces his forward power by wasting energy in keeping his balance. If Bolt were to remain still with his upper body as all good sprinter should, he may be able to propel himself even faster.
Of course the lateral body movement may be a result of other inefficiencies with Bolts mechanics. It is possible that he turns his knees or feet out a little. As Michael Johnson is an excellent proponent of running mechanics and a highly qualified coach, we are sure that he and his team setup their cameras in the best way to measure these inefficiencies correctly.
One of the most important aspects of video analysis for sports is to ensure that we get video images that will allow us to do the analysis we want. If we are interested in Bolts side to side sway we need to have a camera directly in front and or behind him as he sprints down the track. We want to be able to measure how much his body moves laterally and see if his knees and feet are out of alignment. With this information we can help our athletes improve their mechanics and speed.
At the IAAF World Championships in Berlin, the German IAAF Member Federation, DLV, in cooperation with the IAAF is carrying out a major Biomechanics Project.
The project presented the reaction times and splits for all the finalists from the 100 metersemifinals and the final at the 2009 IAAF World Championships in Berlin.
We thought we would present them here and try to predict just how fast Usain Bolt can run.
This table gives us some real insight into Bolt's race. Lets take a look at some crucial points in the race. You can click on the table to see the details.
Of the 8 finalists Bolt has the 3rd slowest reaction time to the gun, at 0.146 seconds. Both Asafa Powell with 0.134 secs and Tyson Gay with 0.144 secs react faster.
By the 20 meter mark though Bolt has caught up all this time and gone ahead of Powell by 0.03 secs.
From the 20 meter mark on, Bolt is away and getting further away over each 20 meter interval. Although we can also see that Tyson Gay is able to hang pretty close between 20 and 80 meters.
Bolt reaches his top speed of 12.27 m/s or 27.45 miles per hour at the 65 meter mark. This can be seen in the second graph presented by the IAAF Biomechanics Research paper.
From 80 to 100 meters Bolt actually begins to slow down. We can see that his time for the last 20 meters is 0.05 seconds slower than his fastest 20 meter split of 1.61 seconds. We also know that he reached his maximum speed at 65 meters and everything after that was a little slower.
One last thing to note is that in this race there is a tail wind of 0.9 m/s. This is legal but it does give the athletes a slight advantage as it pushes them along.
To determine how fast we think he can run, lets look back at the Beijing Olympics and remember how analysis of that race suggested that if Bolt had maintained his speed through the last 20 meters and did not begin celebrations, he could possibly have run the 100 meters in 9.55 seconds.
His current world mark is pretty close to that already, so where can he improve to make up the time. So here are some key factors that are critical to determine how much faster he can go.
Firstly look at the table again and at Bolt's reaction time (RT) for his semi-final. In this race he gets out in 0.135 seconds as against the 0.146 seconds in the final. We also see that he completes the first 20 meters in the same time in both the semis and final, while he definitely seemed to be cruising in the semi-final. It has also been suggested that Bolt actually covered the first 20 meters in Beijing faster than he did in Berlin. This is up for debate though, as if you remember from our post on that study, the video analysis was done using broadcast footage where the camera setup was not optimal. In any case, Bolt can definitely get out of the blocks faster and should be able to cover that first 20 meters faster than he did in Berlin.
The prediction from the Beijing Olympics was based on the suggestion that Bolt could maintain his speed at 80 meters through to the end of the race. In Berlin however, he is not able to do this and slows down a little over the last 20 meters. We also notice that all the athletes in the final ran slower over the last 20 meters, than in the split between 60-80 meters (which was the fastest for all of them). Therefore it may be impossible for a 100 meter athlete to maintain their speed over the last 20 meters and the Beijing prediction may have been optimistic in this regard.
In the last 10 meters in Berlin, Bolt takes a look out of the corner of his eye to check on Gay. We don't believe this could have caused too much of a slow down. In fact if we look at his average velocity at the 90m and the 100m mark from the research, we can see that he does not slow down between those 2 points. But lets assume he could have been 1 or 2 hundredths of a second faster if he had not checked.
The 0.9 m/s tail wind in the final in Berlin will definitely have helped Bolt. A tail wind of up to 2.0 m/s is considered legal for a record to stand. Therefore there is an advantage to be gained with the right conditions.
Finally we have some sort of answer. We think Bolt can definitely run faster. If he improves his reaction time and runs hard through the finish in the right conditions, we have no doubt a new world record will be set.
I am sure we would all love to see an athlete challenge the 9.50 second barrier and Bolt may have it in him to do just that. We look forward to watching it all.
In a recent post we asked the question: How fast can Usain Bolt Run? In this post we introduced you to a study that suggested he could have run the 100 meters at the 2008 Beijing Olympics in less than 9.6 seconds.
At the 2009 IAAF World Athletics Championships, today he proved just that, shattering his own World Record by running the race in 9.58 seconds. Even then he still had time to take a look out of the corner of his eye at Tyson Gay, his closest competitor, who ran an impressive 9.71 seconds
If you missed this amazing race, take a look at the video below.
Unbelievable! The only question left is how much faster can he go? Bolt himself believes that he can run the 100 in 9.4 seconds. To us this seems a bit out of reach, although we believe he will go faster than 9.58.
The IAAF World Championships begins in less than a month and all eyes will be on the 100m and 200m world record holder, Usain Bolt from Jamaica. We all remember the Beijing Olympics in 2008, when Bolt ran the 100m in 9.69 seconds, throwing out his arms and pumping his chest before crossing the line. There has been a lot of speculation about how fast he could have run with some suggesting a time of 9.55 seconds http://sports.espn.go.com/oly/trackandfield/news/story?id=3583692 .
The publishers of the study above, made use of video analysis to estimate this potential world record time. In fact they used video from Beijing Olympics broadcast productions from NBC, BBC and NRK (a Norwegian Channel). If you are a regular reader of our posts you will already know about many of the techniques they used to analyze the video. Lets look at how they did it.
When you or I setup to capture video of a sporting performance, we know how important the position of the camera is. In this case however the researchers did not have access to the stadium and athletes in Beijing and therefore had to make use of broadcast footage. In most cases this footage includes moving cameras and camera angles that are not always conducive to accurate measurement.
The publishers of the article used basic physics to estimate the possible finish time for Usain Bolt had he not celebrated 20 meters before crossing the line. The basic equations are well known: Velocity (speed) = Distance/Time
Acceleration = Velocity/Time So if we can find the distance Bolt covered and the time he took to cover that distance we would have his velocity or speed. We could measure that speed, from the video footage, over numerous intervals to determine how it is changing. Likewise, if we know his velocity (speed) we can measure his acceleration and how it changes over the same intervals.
The publishers of the study estimated Bolts speed and acceleration at the interval before he started to celebrate. At this point his speed and acceleration slow. To determine the predicted finishing time, the researchers assumed that Bolts acceleration could be maintained over the last 20 meters of the race, had he not celebrated. In this way they were able to predict a finishing time of 9.55 seconds.
You probably want to know how they were able to determine distance covered and the time it took. This information was all obtained from the broadcast video. The video used was from NBC and can be found at http://www.nbcolympics.com/video/share.html?videoid=0824_HD_ATB_AU_CE552 . Below is similar video of the race :
In the video you will see the camera rail running from the left to the right at the bottom of the image. This camera rail has bolts spaced evenly along it. By knowing the distance between the bolts on the track and that the start line is at 0 meters and the finish line at 100 meters, we can determine Usain Bolts position relative to the rail bolts at numerous intervals.
You will also see the stadium time clock and the broadcast time clock in the video. These clocks can be used to determine the time at which Bolt reached each interval.
We now have all the information we need. Distance covered and the time it took. From this we can determine his speed and acceleration at all intervals and predict his finishing time had he not begun his celebrations early.
We would like to thank the study authors H. K. Eriksen, J. R. Kristiansen, Ø. Langangen and I. K. Wehus for doing this fun study and we look forward to seeing whether Usain Bolt can get anywhere close to this predicted World record at the IAAF World Championships in Berlin in August.
Please let us know if you want more details on this study or just want to leave a comment. We love to hear from you.
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