There are a number of things I look for an think about when analysing a 1/2 Ironman race performance on the bike.
1) Was there a plan and was it executed?
2) How consistent was the effort relative to the course profile?
3) How intense was the effort relative to their threshold ability?
4) How was the race influenced by competition eg drafting effects?
5) Did they run well and was the nutrition sufficient?
6) What can we learn from it?
This is the power file for Jennifer Stewart the female winner of the Highland Warrior middle distance Scottish championship race in Fort William on Sunday.
Jen rode 2 hours 34 minutes for the 90k with an average power of 214 watts and normalised power on 216.
She went out with the simple plan to maintain a stable power output between 200-220 watts but afterwards revealed that she believe that she had intentionally increased her power output in the second half. The reality was remarkably the average on the outward leg (uphill with a tail wind) is identical to the return leg showing how our perception can mislead us in our pacing and a pacing strategy bassed of even effort will always result in a drop off in power.
The variability index (VI) for this ride is less than 1.01. This is a measure of how even the effort and stable the power output was. 1.01 is exceptionally stable for a course with 600m of climbing and challenging conditions. Jen certainly has a talent here as many triathletes would struggle t0 achieve this on a indoor trainer. I would consider anything up to 1.04 to 1.05 good for a course like this (my own ride was 1.03) but is very much about knowing what you do and trying to improve it.
In terms of tactics and competition there is little evidence for Jen deviating from her plan. There are no drafting effects apparent which become easy to spot when you have seen a few Ironman power files! Having your plan upset by the competition is something that can seriously affect your race and the more you can ignore what is going on around you or up the road the better you will finish the race.
Thinking about intensity we can look at the ride either as a simple %ftp or look at the training stress (TSS) score. The ride was between 80-85% ftp power so very controlled with a TSS of 186 wich is high due to the length of the ride in poor conditions. In fair conditions Jen could have expected to go quicker for the same power with a lower TSS but this is still well within the range you would expect to be able to run well. The correct range will vary dramatically between 70-90% depending on your fitness but broadly speaking a TSS between 170-190 is in the safe range but over 200 risky.
Jen ran very well of this bike producing close to her PB half marathon time on a difficult course so we can say her nutrition was adequate and pacing appropriate.
Looking at Jens cadence average of 77 and how she worked her strength vs aerobic power I check the quadrant analysis (QA). Looking at this you can see that the work falls down to the left indicating lower power, lower cadence, which is ideal for a longer race. To improve on this Jen could try and reduce the spikes in the top left. If we look at the short 2-30sec power spikes this is where they fall typically steep climbs and accelerations and high power but low cadence. These will affect your run so the fewer of these spikes you can achieve the better. Also “spinning” in the bottom right quadrant wastes a lot of energy. Remember the T-cadence is your own 40k TT cadence not always 90rpm.
Could she have therefore pushed harder perhaps and ran well? Possibly but this is something to practice in training or in training races. A run test following a hard 2 hour or 50mile TT at a higher average power would be appropriate for someone of Jens level. We have certainly learned she has a great feel for pacing and power and can run well of a bike at this intensity.