The Ironman World Championships in Kona are legendary, not only for triathletes. It is the defining race in this sport for any avid triathlete. The idea of an endurance triathlon, combining three major events that already existed on the island, was founded in 1977 by a group of local athletes. The winner would be called IRONMAN. More than 30 years later the idea and the event are one of the most respected sports events in the world. What makes it unique is that the „average" athlete can compete alongside the best in the world and every finisher is a winner.
But to get to the starting line in Kona, you must either be very lucky and get yourself a spot through the lottery, or be very talented, and win yourself a qualifying spot at one of the qualifying events held around the world. Tens of thousands of triathletes try to get one of those coveted Ironman spots every year. Only 1,800 succeed. That means 1,800 "lucky" people get to test themselves at one of the biggest challenges the sporting world has to offer ... 3.5 kilometers of swimming, 180 kilometers of biking, and a 42 kilometer marathon run through tough ocean waves, and challenging lava-covered terrain.
We want to present the SRM data of two athletes who rode the bike leg with an SRM PowerMeter. The hilly course along the lava-covered terrain is very demanding, especially because of the heat and sometimes gusty winds. When competing in an IronMan, it is very important to follow an intelligent pacing strategy to keep a steady pace and avoid overpacing. When you're riding for five or more hours, making a pacing mistake is merciless, particulary when it happens before the marathon run.
Asker Jeukendrup was born in Roermond in the Netherlands in 1969. He is one of the leading sports nutritionists; he is director of the Human Performance Lab at the University of Birmingham and in charge of one of the most active sport and exercise research groups. At the age of 35 he became the youngest professor at the University of Birmingham and has received several awards for his academic achievements and contributions to sport and exercise sciences, including a chair at the University of Brussels.
Asker is the author of several books including High Performance Cycling and a Textbook on Sports Nutrition in collaboration with Prof Michael Gleeson (see books at http://www.askerjeukendrup.com/books.html). Asker has published over 150 peer reviewed journal articles and book chapters and has made it his mission to translate the science into practical applications that will benefit people who want to achieve their individual exercise goals, whether this is medals at Olympic Games or simply exercising for health reasons.
Over the last few years Asker worked with some of the best athletes in the world, including several Olympic and World Champions; he also worked with the Rabobank professional cycling team, Chelsea FC, UKAthletics, Ethiopian marathon runners, and some of the best swimmers and triathletes. Besides that, Asker is a 16 time Ironman finisher, including 3 times in the Ironman World Championship in Hawaii, he was national champion in Duathlon in his age group, and won the San Francisco Golden Gate Headlands Marathon amongst other sporting achievements. His ventures have not gone unnoticed and Asker appeared in various TV programs and featured numerous newspaper articles and magazines.You will find further information on www.askerjeukendrup.com
Asker finished the IronMan World Championships 2008 in 10:52:08 h (swim: 1:21:29 h; bike: 5:20:15 h: run: 4:03:37 h).
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It is pretty interesting to look at the analysis graph:
Remember the rainbow line in the top right of the screen? It tells you the order that the data happened in (yellow at the beginning of the race, then red, then green, etc....).
In the beginning (yellow) Asker pushed hard and his heart rate stayed low. A lot of triathletes are pretty exhausted after the swim. Not so for Asker, who was right when he said he felt good after the swim. Maybe he didn't swim very fast, but he kept energy for a good start to the bike ride.
After about 80km the stomach problems started, that's the green section of the line. His heartrate went up and the line is above the best fit line, he had to push less power as you can see in the light blue section. The line moves to the left (less power), but than he recovered and the line moves below the average line, the heart rate dropped and he recovered for the next part of the race (dark blue line). It seems that this effort was a little too hard, because the heart rate goes up, in the last part of the race (magenta line) he had to lower his wattage again, but this is also to be not too exhausted for the run.
His R2 value was 0.30 (which just means that the best fit line explains 30% of the relationship between heart rate and power) - the higher the better (remember the Tour de France riders had between 0.70 and 0.95 due to their very well adapted fitness and metabolism), because we can presume that beside carbohydrates, a large amount of fat will be used for energy metabolism. For Asker, who had a one day effort and a perfect „refueling" technique this is not as important.
Have a look at the slope: 0.12 1/Wmin. That is really low! And good! For every 100 Watts that he increases his power, his heart rate goes up 12 beats (starting from his lowest exercising heart rate, 118.97 bpm - where the best fit line hits the y-axis). That means that at 100 Watts his heart rate is 131 bpm, and at 200 Watts it is 143 bpm.
The reason for the low slope might be his good pacing strategy. No really hard efforts during the race, just right at the beginning he went harder to leave the transition area. As every point on the line represents a 4min average (due to smoothing 4:00 min) he pushed with 485 Watts average for the first 4 minutes.
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Wolfgang Teuchner is a young German triathlon talent, born in 1984. He won his age group in 2009 at the European Championships in Frankfurt.
Wolfgang Teuchner's SRM data from the IronMan World Championships in 2007 show a significant drop in power after the first half of the bike split. He started with a 1:00:24 h swim and left the water as 255th. In the first hour on his bike he was able to push a very high power: 350 Watts (4.3 w/kg). Wolfgang is known as a bike specialist in triathlon, but obviously he overestimated his power this time. Normann Stadler rides with about 300-340 watts average, Faris Al Sultan with about 300 watts for the whole IronMan. Their average speed is about 40km/h. In the first half the average power is normally a little higher than in the second half which is more downhill. But Wolfgang was not able to keep his power after the downhill to Hawi - with an average of 220 Watt (2.7 w/kg) for the second 90 kilometers his power was 34% lower than in the first half (335 w / 4.1 w/kg).
Possible reasons for a huge drop in power like this are: overpacing in the beginning, bonking because of a non-sufficient energy intake, insufficient fluid intake or heat acclimatization, but also individual factors like a viral infection right before the competition. It's a shame that we don't have the heart rate curve, which could give a better explanation.
Even though Wolfgang had a hard time in the second half of the bike leg, he finished in the Top 100 on the bike (83th). With 3:40:39h for the marathon he finished 211th at the IronMan World Championships in 2007, and gained a lot of experience for the years to come.
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Aerodynamics are a very important factor in IronMan triathlon. Drafting is not allowed so the athletes try to optimize their bikes and their position. But in contrast to time trial specialists in professional cycling, their position on the bike is not as extreme.
To ride a 50km time trial is something different to 180 km and be able to run a marathon after, so it is a balance between aerodynamics and comfort. In training this means getting used to better aerodynamic positions, and keeping them as long as possible. Functional training, flexibility and the ability to develop strength even if the hip flexion is more extreme and cramping of the hamstrings becomes more likely, has to be practiced.
Most world class athletes do aerodynamic testing on the track and/or in the windtunnel. But even a simple roll-out test or your data riding a specific, well-known test terrain can help a lot to find out if you get faster (speed), more powerful (power), and/or less exhausted (heart rate). There are a lot of variables that can interfere. But still, it's a start to get faster.