Miranda Griffiths’ Battle on the Border Power Analysis
The Battle on the Border was the second race in this year’s Subaru Women’s National Road Series and it was run and won earlier this month. Miranda Griffiths from Holden Women’s Cycling finished second overall and has been good enough to provide us with the power data from her victory on stage 1. We asked Helen Kelly from Kelly Cycle Coaching to pull apart some of the numbers in Miranda’s power file, to give us a sense of what’s required to win a women’s NRS race.
Before we get to the analysis of Miranda’s power file, here’s a bit of context about the race.
Stage 1 of the women’s Battle on the Border was a 93.9km road race featuring a couple of loops that started and finished in Murwillumbah in north-east New South Wales. The race featured a handful of short but reasonably steep climbs but no sustained rises of more than a couple of kilometres (see the profile here).
Here’s how the stage unfolded according to Miranda:
By my standards the stage was relatively flat. We didn’t have a team sprinter so we knew we had to make the most of the few climbs that we had to try to establish a break. The team plan going into the race was for my team mates to drive the first climb to make the race hard then I was going to attack the second climb with the hope of getting away with a small group. As it happened Ruth Corset (Pensar SPM Racing) beat us to it.
To start everyone was fighting for position but there were no real attacks. 12km in Chloe McConville (Victorian Institute of Sport) attacked and I followed. A small split formed but no-one really wanted to push on. Everything then came back together at the bottom of the first climb.
Ruth attacked from the bottom of the climb. I jumped on her wheel and Emily Roper (Suzuki Bontrager) followed me. We kept pushing all the way to the top of the climb. I looked over my shoulder and couldn’t see anyone so we started working. By the top of the second climb at around 19km the commissaire told us we had around a one-minute lead.
The three of us all worked well together with the time checks constantly going up and down. I wasn’t sure we were going to be able to stay away. At one stage the time gap came down to around 30 seconds but every time we hit a climb we were able to push the time gap back out to more than a minute. Emily dropped off on the climb at around 56km and we pushed on without her.
Ruth and I worked all the way to the finish and at around 500m to go we started to slow down and watch each other. Ruth jumped early and I jumped straight onto her wheel. I sat there until I saw her fading then jumped and came round her at the finish.
Here are some stats about Miranda:
- Threshold wattage: 250W
- Weight: 47kg
- Power/weight at threshold: 5.3 w/kg
And here are some stats about Miranda’s effort for the race:
- Average power: 210 watts
- Normalised power: 228 watts (learn about normalised power here)
- Work: 1941 kilojoules
- Elevation Gain: 738 metres
- Race duration: 2 hours 34 minutes
- Training Stress Score: 214 (learn about TSS here)
- Intensity Factor: 0.914 (learn about intensity factor here)
- Average speed: 35.2 km/h
- Maximum speed: 73.8 km/h
- Average cadence: 95 rpm
- Maximum cadence: 127 rpm
- Average heartrate: 163 bpm
- Maximum heartrate: 181 bpm
Here how Miranda’s power (top third), heartrate (middle) and cadence (bottom) varied throughout the race. You can click on the image below for a larger, more detailed view.
And here’s how much of the race she spent within each speed, cadence, heartrate and power range:
Here are a few things that stood out to us about Miranda’s ride:
- She spent nearly half the race (1 hour 15 minutes) spinning at between 90 and 100 rpm and another 46 minutes at between 100 and 110 rpm.
- Her peak power of 737W (15.7 w/kg) didn’t come in the sprint at the end of the race, rather it was when Chloe McConville attacked after 12km and Miranda followed the move.
- In the final 20km of the race, when it was just her and Ruth Corset riding together, Miranda averaged 227W (4.8 w/kg) and had an average speed of 38.6km/h.
- In the final sprint, which lasted 36 seconds, Miranda reached a peak power of 660W (14 w/kg) and averaged 370W (7.9 w/kg). Her peak speed during the sprint was 46.8 km/h. You can see the final part of Miranda’s sprint at 2:04 in the video below.
Miranda spent 35% of the race above her threshold power of 250W, which can be broken down as follows:
- 250-300w: 23.6% of the race (50 minutes)
- 300-350w: 8.1% of the race (17 minutes)
- >350w: 4.5% of the race (10 minutes)
She spent 7 minutes 30 seconds (3.6% of the race) free wheeling and a total of 52 minutes (24.3% of the race) in her recovery zones (i.e. less than 140W, or 3 w/kg). The longer an athlete can remain well below threshold during a race, the more likely they are to be able to unleash their maximum power/energy when needed.
The following best efforts during the race all happened from the 11km mark, when Miranda marked Chloe McConville’s attack and in the resulting break that included Emily Roper and Ruth Corset:
- Best 5 seconds: 714W (15.2 w/kg)
- Best 30 seconds: 514W (10.9 w/kg)
- Best 1 minute: 382W (8.1 w/kg)
- Best 10 minutes: 256W (5.4 w/kg)
So what does all this mean? Well, a few months ago we analysed Tiffany Cromwell’s power file from her winning ride at Het Nieuwsblad. While there are many factors that make it difficult to compare Miranda and Tiffany and their races directly, you can see that Miranda’s numbers (threshold power and power-to-weight ratios) are world-class.