Power Analysis: Jacques Janse van Rensburg Achieves a Personal Best in the 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 Data Amstel Gold La Flèche Wallonne Liège–Bastogne- Liège
Distance (km) 261km 200.5km 258km
Duration (hh:mm:ss) 06:34:35 05:16:54 06:25:19
Time behind winner (mm:ss) 02:55 01:17 00:54
Finish Position 48 58 41
Average Speed (kph) 39.7 38 40.2
Total Ascent (m gained) 3155 2480 4126
Average Power (W) 235 225 246
Normalized Power (W) 299 290 300
Normalized Power (W/kg) 4.7 4.6 4.8
TSS 443.7 336.6 438.7
Work (kJ) 5553 4284 5468

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 Hour Amstel Gold La Flèche Wallonne Liège–Bastogne- Liège
Average Speed (kph) 39.4 40.3 42
Total Ascent (m gained) 502 772 712
Average Power (W) 274 298 287
Normalized Power (W) 329 355 351
Normalized Power (W/kg) 5.2 5.6 5.6
TSS 81.6 95.1 93.4
Work (kJ) 989 1074 1042

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 63km Distance (km) Ave Gradient (%) Duration (mm:ss) Average Speed (kph) Average Power (W)
Climb 1 4.36 6% 10:52 24.1 347
Climb 2 2.49 6% 05:48 25.8 357
Climb 3 2.03 9% 06:01 20.3 406
Climb 4 1.08 11% 03:48 17.2 433
Climb 5 1.17 9% 03:32 20.7 431
Final Climb to Finish 1.34 6% 02:52 28 415

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.

About the Author

Trevor Court

Trevor Court is a Coach at Team Dimension Data for Qhubeka who works from the team’s European Performance Center in Lucca, Italy. He is a South African graduate sports scientist and has been working with the team since 2011. Trevor is particularly passionate about developing young talent for the pro peloton.

View more posts by Trevor Court