Power Measurement in Women’s Pro Cycling

Tiffany Cromwell’s Omloop Het Nieuwsblad Power Analysis

by Wade Wallace
and Helen Kelly

This post was first published on Cycling Tips.com.au at http://cyclingtips.com.au/2013/03/tiffany-cromwells-omloop-het-nieuwsblad-power-analysis/
It is a rare glimpse into how accurate power measurement is used at the forefront of professional cycling. I have added it to our posts here as I felt the article was so good in the way it talked about women’s cycling.

As most of you will know Tiffany Cromwell won Omloop Het Nieuwsblad last weekend and I had the opportunity to interview her a few days ago. I thought it would be interesting to do an analysis of Tiff’s SRM data from the race to put into perspective how good these girls are. Tiff was generous enough to oblige and send me her files. I’ve ridden with Tiffany and some other top women cyclists in the world and let me tell you, they’ve given me a whoopin’. This one’s for you power geeks out there. Have a look and don’t let the graphs intimidate you …
I asked Helen Kelly of Kelly Cycle Coaching (Melbourne) to help me with the analysis since she trains all her athletes with Training Peaks and is very familiar with the software. Not only that, Helen use to race at an international level and in the final race of her professional career, she was in a breakaway with Tiffany Cromwell as a young amateur at the Bay Crits (the Geelong hot dog circuit on Richie Blvd). They both stayed away for the entire race and Tiff attacked on the bell lap but Helen got to her by the final corner and just came around her moment before the finish. Helen was at the end of her career, Tiff was at the start of hers.

Anyway, back to Tiff’s power analysis. A few facts and observations:

  • Tiffany weighs around 49-50kgs.
  • Tiffany’s threshold power (tested in January) is 229 watts. This equates to a threshold power of 4.6 watts/kg.
  • We’ll see male pros at the top of climbs with threshold power levels of 6.2w/kg, and back in the day it was closer to 6.9w/kg.

We can also see from the charts below a few interesting things:

Tiffany appears to be very good at keeping her nose out of the wind, because she spent 25mins below 60w and 30mins at 60-120w (i.e. in her recovery zones). This basically means that she was able to conserve a lot of energy when she could. Even more so, with her overall average numbers being so high, it shows that when she was going hard, she was going extremely hard! For 73 minutes she was over her threshold power.

Another thing to take into account are the cobble sectors and how much more effort they require than smooth roads. Also keep in mind that the point of racing is to conserve as much as possible until the decisive moment. Only use what you need and save everything for the finish. If you expect higher power figures because you’re use to hearing the men’s wattages, keep in mind through all of this is that Tiffany weighs only ~50kg.


  • Total race time: 3:36
  • Average power 175W
  • Normalised power 206W
  • TSS 292.9
  • IF 0.903

Let’s get more into these power stats during the key moments of the race.


Here you can see the distribution graphs for speed, cadence, HR, and power. Things to take from this: Don’t pay much attention to speed — it means nothing in a race; Tiffany’s cadence was a nice 80-90rpm for most of the race. Her power was either very low, or above her threshold, and HR was in the 160bpm area for much of the race.


This is Tiffany Cromwell’s overall Omloop Het Nieuwsblad graphs for power (top), heart rate (middle) and cadence (bottom) for the entire 3 hours and 36 minutes of the race. From this you can see a couple of things. Her average power was 175W (she weighs 50kgs), her normalised power was 206W and she burned 2244kJ. What’s really interesting is that her TSS (training stress score) was 292.9 (which is massive) and her IF (intensity factor) was 0.902. TSS is a Training Peaks metric (this is the software we’re using). Basically what it means is that 1hr spent at your threshold would equal a TSS of 100. Tiffany nearly scored the maximum achievable TSS each hour she raced. Same thing with the IF (intensity factor). The maximum possible IF is 1.0. Tiffany scored just under that (IF is used to calculate TSS).


This shows the final 20kms of Omloop Het Nieuwsblad where Tiffany was in the final break. With all eight climbs completed and five cobbled sections yet to come, a 16-rider front group formed. There were multiple attacks from many riders but nothing stuck. You can see that Tiffany averaged 224W (just under threshold) in this period before she made her final move which won the race.

Cromwell attacks before the final pavé sector with 11km remaining. “We had been using our numbers to our advantage and launching attacks that were going nowhere,” said Cromwell. “Finally, I went and Megan Guarnier came with me. We got a gap immediately but she wasn’t working with me. I still considered it a good opportunity, so I worked – maybe a bit too much. Eventually Megan started rolling through. It was enough to hold off the chasing bunch.”


This graph shows where Tiffany made her final attack 11km from the finish just before the final pavé sector. She put out nearly 700W in her attack and then held a normalised power of 240W for the final 17mins. Her max HR was 173 and she had an average speed 34.7km/hr in that last section of the race. We can see the power spike at 300m from the end where Tiffany tops out at 749W. At approximately 50kg, this is normalised to 15w/kg. The highest ever recorded peak power from a female at the AIS that we could find is 16w/kg.

Cromwell forced Guarnier to the front just before the final kilometre. With a long sprint still to go, Cromwell came around Guarnier to open up the sprint but Guarnier nothing left to react. “I started sprinting with 300 metres,” Cromwell said. “Megan didn’t contest the sprint. I don’t think she had anything left.”