Power Analysis: Jacques Janse van Rensburg Achieves a Personal Best in the Ardennes Classics

Power Analysis: Jacques Janse van Rensburg Achieves a Personal Best in the Ardennes Classics

An analysis of Team Dimension Data for Qhubeka’s Jacques Janse van Rensburg at the 2017 Ardennes Classics.

During the third week of April Jacques Janse van Rensburg (JJvr) from Team Dimension Data for Qhubeka raced the Ardennes Classics; Amstel Gold (AG), La Flèche Wallonne (LFL) and Liège–Bastogne- Liège (LBL). Jacques provided excellent in-race support to the team’s designated lead riders and also achieved personal best career results (48th, 58th, 41st respectively).

Summary of Ardennes Classics Data

The Ardennes Classics are hilly, one-day UCI World Tour races raced over an eight day period in April. They are extremely demanding, as is reflected by Jacques summary data in Table 1. The TSS scores and work scores for the 2017 editions of AG and LBL  (444 and 439 respectively), are amongst the highest race day scores that Jacques has on record.

Table 1: Summary Data for Ardennes Classics

Summary DataAmstel GoldLa Flèche WallonneLiège–Bastogne- Liège
Distance (km)261km200.5km258km
Duration (hh:mm:ss)06:34:3505:16:5406:25:19
Time behind winner (mm:ss)02:5501:1700:54
Finish Position485841
Average Speed (kph)39.73840.2
Total Ascent (m gained)315524804126
Average Power (W)235225246
Normalized Power (W)299290300
Normalized Power (W/kg)4.74.64.8
TSS443.7336.6438.7
Work (kJ)555342845468

While the overall race summary data is impressive, the work done in the last hour of racing highlights the effort required for a winning performance. In the final hour of all three races there is a difference of approximately 60W between Jacques’ average and Normalized Power. This difference highlights the fluctuations in intensity (accelerations) as the peloton fights for position in the race to the finish line.

Table 2: Final Hour of Racing

Final HourAmstel GoldLa Flèche WallonneLiège–Bastogne- Liège
Average Speed (kph)39.440.342
Total Ascent (m gained)502772712
Average Power (W)274298287
Normalized Power (W)329355351
Normalized Power (W/kg)5.25.65.6
TSS81.695.193.4
Work (kJ)98910741042

Liège–Bastogne- Liège

You can see Jacques’ file from LBL here or by clicking on the image below. His data was measured by a Rotor2IN power meter and recorded on a Garmin Edge 820.

04116-power-analysis-jacques-janse-van-rensburg-ardennes-classics-fig1

An analysis of the final 1:30hr/63 km of LBL highlights the intensity at which the riders worked over the final six climbs as is detailed in Table 3 and Fig 1. The racing became progressively harder as the domestiques worked to drain the last remaining energy from their competitors’ legs while providing cover for their team’s protected rider.

Table 3: Final Six Climbs of Liège–Bastogne- Liège

Climbs in Final 63kmDistance (km)Ave Gradient (%)Duration (mm:ss)Average Speed (kph)Average Power (W)
Climb 14.366%10:5224.1347
Climb 22.496%05:4825.8357
Climb 32.039%06:0120.3406
Climb 41.0811%03:4817.2433
Climb 51.179%03:3220.7431
Final Climb to Finish1.346%02:5228415

Fig 1: Power Output (W/kg) on Final Six Climbs of Liège–Bastogne- Liège for JJvR

04116-power-analysis-jacques-janse-van-rensburg-ardennes-classics-fig2

These types of analysis are performed regularly by our team coaches. The data helps to direct the rider’s specific preparation and training and as well as their in-race effort and energy management.