Pro Power Analysis: Stages 18-19 at the Tour de France

Sky and Chris Froome celebrated victory on Sunday at the 100th Tour de France. Cycling is a team sport and Froome has depended on complete dedication from his teammates throughout the non-stop excitement and unpredictable events of the first 20 stages. They definitely came through — including Spanish climbing domestique David Lopez, who shared his power data with TrainingPeaks. Let’s compare his data from the two epic mountain stages of the Tour, stages 18 and 19.

Stage 18 is one that will be forever remembered as the double Alpe d’Huez stage. For the 100th anniversary of the Grand Boucle, racers completed two ascents of the famous climb in the second half of the stage and also summited four additional categorized climbs, resulting in an official tally of 4,304 meters (14,120 feet) of climbing over 173km. Lopez’s time was 5:16:42 and he finished 70th. His summary stats for stage 18 can be seen below.

Stage 18 summary

262 Average Watts
3.9 w/kg
314 Normalized Power (NP)*
341 Training Stress Score (TSS)**
5,093 Calories
141 bpm Average Heart Rate
82 rpm Average Cadence
31.7 kph Average Speed

*NP is an estimate of what the power output would be if it had been perfectly constant — a better way than “average power” to quantify the true physiological cost of a ride.

**TSS quantifies the stress of a ride given its intensity and duration. A one hour, all-out effort would be 100 TSS.

View David Lopez’s SRM data from Stage 18 in TrainingPeaks.

The following day in stage 19, riders faced even more climbing: 4,562 meters (16,223 feet) was the official elevation gain over five categorized climbs, including the legendary Col de la Madeleine and the Col du Glandon in the first half of the stage, while racing a total of 204.5km. Lopez’s official time was 6:22:51, 62nd that day.

Stage 19 summary

251 Average Watts
3.7 w/kg
297 NP
363 TSS
5,814 Calories
137 bpm Average Heart Rate
78 rpm Average Cadence
31.3 kph Average Speed

View David Lopez’s SRM data from Stage 19 in TrainingPeaks.

Each stage had two huge climbs, but at opposite ends of the stages. In Stage 18, Lopez averaged 360 watts (5.3 w/kg) for about 45 minutes on the first ascent of Alpe d’Huez as he helped to defend the yellow jersey. On the second ascent, with Froome safely up front, Lopez averaged just 288 watts (4.2 w/kg) and took about 10 minutes longer. He set his 30- and 60-minute peak power values for the stage on the first time up, 367 watts (5.4 w/kg) and 334 watts (4.9 w/kg), respectively.

In contrast, stage 19 brought the climbs early, in the first half of the stage. Lopez averaged 305 watts (4.5 w/kg) on the Col du Glandon, taking about an hour to complete the 21.6km climb that averaged 5.1 percent. On the slightly steeper Col de la Madeleine, he averaged 325 watts (4.8 w/kg) and also set his 30- and 60-minute peak power values, 327 and 326 watts (4.8 w/kg).

In stage 18, Lopez set his peak power values on the earlier of the two biggest climbs, at the end of the route. In stage 19, peak power values were achieved on the second of the two toughest climbs of the day, which occurred in the first half of the stage.

It does appear, as would be expected, that Lopez was a little more fatigued on stage 19. On average, his power values were not quite as high as the previous day — for example, he dropped from 367 watts to 327 watts for 30 minutes. However, on stage 19 he was more consistent on the climbs. He averaged 4.5 w/kg on the Col du Glandon and 4.8 w/kg on the Col de la Madeleine, actually putting out more power on the second climb. The previous day, on the first Alpe d’Huez ascent, he averaged 5.3 w/kg and dropped to 4.2 w/kg on the second time up.

What causes these differences and similarities? There are many factors that need to be considered. Fatigue is clearly having an impact, but everything from team roles and duties, the gradients and lengths of the climbs and where they occur in the stage, to weather, equipment, and the race situation (where is the breakaway, the competition, etc) all factor in.

This has arguably been one of the most exciting and dynamic Tours in recent years and it has been a privilege to review so many of the riders’ files from every stage. TrainingPeaks would like to thank all of the riders who have shared their data, and congratulate Sky on their second Tour de France victory.

For more power data from the Tour de France, visit TrainingPeaks.com/TDF.

Editor’s note: Thanks to TrainingPeaks.com, we are looking at power data from the 2013 Tour de France. Today, Shawn Heidgen, a USA Cycling certified coach, former professional cyclist, and Education Specialist at TrainingPeaks, recaps the data from stages 18-19 of the three-week race. For more, follow Shawn on Twitter.