Although the prologue is the shortest event in the Tour de France it is by no means the easiest. At 7.9 km, the 9- to 10-minute all-out effort involved in the prologue is excruciating, requiring the complete utilization of both oxidative and non-oxidative energy systems. Generally speaking, this means that the athletes who do best in the prologue have the best combination of both aerobic and anaerobic power. That said, every athlete is different and for this time frame, some athletes better known as long time trial specialists or climbers may produce the majority of their power through aerobic systems while other athletes better known as sprinters or as pure prologue specialists may rely more on their anaerobic power.

Regardless, the prologue is a gut-wrenching effort that requires extraordinary effort, focus and, of course, fitness. Historically, this means that the winner of the Tour will generally make the top 10 in the prologue despite not being a prologue specialist. Still, the short time frame of the prologue means that a lot can go wrong. One bad corner, a slight loss of concentration, or a mechanical can mean the difference between making the top 10 or settling for the top 50. In addition, at between 30 to 33 mph, aerodynamic drag is the primary form of resistance holding back the riders on the essentially flat prologue course. Thus, decreasing aerodynamic resistance is as important if not more important than an athlete's ability to produce power during the prologue.

In today's prolgoue, Fabian Cancellara put in a truly amazing performance. In fact, I can't recall a rider putting in that dominating of a performance in the prologue since Chris Boardman set the Tour prologue speed record of 55.12 kph on a 7.2-km course in 1994. At 53.59 kph (33.2 mph) over today's 7.9 km course, I estimate that Cancellara had to maintain an average power of 541 watts (See this chart). This would give him a power-to-weight ratio of 6.94 watts per kg. If all of his power came from only aerobic energy sources, then his maximal aerobic capacity or VO2 max would be, at the very least, a stunning 88 ml/kg/min (average Tour rider is about 75 ml/kg/min).

In contrast to Cancellara's performance, the next fastest time was Andreas Kloden who was almost 13 seconds slower. Though not as fast as Cancellara, Kloden's ride makes him one of the main athletes to watch at this year's Tour. For his time, I estimate that Kloden needed to average 462 watts. This gives him a power-to-weight ratio of 7.11 watts per kg, which is extraordinarily high for an athlete not known as a prologue specialist. What's more interesting is that despite finishing 3rd overall in last year's Tour, Kloden only finished 24th in the 2006 prologue--a 7.1-km flat course very similar to the course in London. In last year's prologue, I calculate that Kloden only averaged 400 watts. Thus, his estimated 62 watt gain is fairly remarkable and if he maintains that form through the next three weeks, my thought is that he could easily be this year's winner depending upon how his Astana team decides to play things tactically. With Vinokourov's seventh-place ride, there is no doubt that Astana is the strongest team in this year's Tour.

Another interesting result I noticed in today's prologue was the fact that only two riders from last year's top 10 made the top 10 again this year. Those riders were George Hincapie (464 watts in 2007 vs. 460 watts in 2006) and Vladimir Karpets (485 watts in 2007 vs. 465 watts in 2006) with Dave Zabriskie (434 watts in 2007 vs. 423 watts in 2006) just missing at 11th place. The rest of the top 10 was made up of four riders not in the 2006 Tour (Cancellara, Gusev, Vinokourov, and Dekker) and four riders making from extremely significant improvements to slight improvements over their performance in 2006.

Finally, I couldn't help but notice the strong ride of Bradley Wiggins (4th) and David Millar (13th) in their home country. Both riders made improvements over their prologue performance from last year. In an event with so little allowable margin of error, it's nice to see riders still elevate their performance when it really counts. In the end, this year's Tour won't only be made with great power, equipment and tactics, it will be made with the heart and passion of some truly incredible athletes and support staff. In the end, it's not so much about the science as it is the intangible spirit of the human will. With that in mind, I look forward to not only giving Active readers some scientific insight at this year's Tour but to also shed some light on the more human side of the greatest race in the world.
--Allen

Dr. Allen Lim received his Ph.D. in Integrative Physiology at the University of Colorado at Boulder. Prior to obtaining his doctorate, Dr. Lim did his undergraduate training in Exercise Science at the University of California at Davis and completed his master's degree in Exercise Physiology. Dr. Lim has extensive coaching experience. He guided the UC Davis Cycling Team to its first national championship and coached the resident national cycling team at the US Olympic Training Center. He has also coached numerous amateur, professional, and Olympic athletes. He founded and acted as the full-time director of the Celestial Seasonings Professional Cycling Team and serves as the Director of Education for the Saris Cycling Group, Dr. Lim is also a partner of ThriveHFM, a health and fitness management consulting group, as well as the Director of Development for the Boulder Life Performance Center.