Friday, October 25, 2013

The Evolution of Luke McKenzie Part 2 - Kona 2011-2013

After my last post, many wondered how Luke's cadence was in 2011, when he finished 9th, and ran 3:05 off the bike in the Kona. It was a great question, and I was luckily able to retrieve Luke's file from 2011, so now we can actually compare his last Kona performances.

***I must give full credit to Hunter Allen of the Peaks Coaching Group, for the article he did on Luke's 2011 Kona ride for a now defunct tri magazine, as he supplied the 2 file photos and the actual power file for this post.***

So the general premise of what I am asking with these posts is, was Luke McKenzie's change to a higher cadence, (90+, which is 20 rpms more from 2012 to 2013), one of the biggest, if not the biggest, reason for his breakthrough race, both on the bike and for the run?

Before I go on to present evidence, let me say I am not certain of this, as there are so many factors affecting performance, especially preparation, conditions, race circumstances and decisions of the competitors, and more. However, this change in riding style and performance was so great, it is unprecedented, and we must examine it closer, not just shrug it off as coincidence. It is especially compelling when we look at how Pete Jacobs rode to win in 2012.

So let's look at the basic info for Luke's ride in 2011, compared with 2012 and 2013: (Click on all images to enlarge)

Here's an image of his actual power file:

Here's an image of Luke's 2011 QA from the race:

The first thing you'll notice is his higher cadence than 2012, but his overall sample average is still in Q3. Here's the breakdown by quadrant for each year:

Many have said 2011 was a higher cadence year, and they are right. However, looking at the above chart, you can see even though he had more time in Q4, (90 rpms or higher), he still had an average which was weighted heavily in Q3, and his average cadence for the whole ride was less than 90, at 86. His reduction of ~40% of his total ride time for 2013 in Q3 compared with 2011-2012 is incredible.

Perhaps he rode too low still, and 86 rpms just wasn't high enough to see the advantages of the higher cadence. But let's look deeper, and compare what I call Cadence Fade/Power Fade. This is a new measurement I created, where I isolate the first hour and last hour of an Ironman bike, to see how the effort fatigued the athlete. I compare the average cadence and the normalized power for those 2 hours, and calculate the percentage lost or gained.

In the above chart, I have sorted the years by place, with his worst finish, 2012 at the top, 2011 in the middle, and his best performance at the bottom. A few interesting correlations as finish place improves, (albeit this is a small sample size), are:
- Cadence was higher both in the first hour and last hour as place improves
- The percentage loss of cadence fade is lower as cadence goes up, and place improves
- The percentage loss of power is lower as cadence goes up
- Run splits get faster as cadence goes up and cadence fade goes down
- IF goes up, but given the power conditions can play on this, it seems to lack any credibility

Perhaps just as interesting is that TSS for ride, NP entire ride and VI ride show no statistical relevance.

Of course, as place improves in the race, you would expect fitness and preparation to be better. One item of interest is that actually in 2011, Luke's reported FTP was 330 watts, when he got 9th. In 2012 and 2013, his worst and best performances, it is reported at 360 watts. Does this negate the preparation argument, since he had a higher FTP or better bike preparation in 2012 and 2013? Of course not. After all, FTP is only one measurement of fitness. But one could also argue that if Luke made the decision to ride over 90 rpms, (which he clearly did), he made a decision to better prepare himself to do so, and executed that. Which would give credence to the fact his preparation was more effective when he focused on going over 90 rpms.

Was it because he did the race over 90, or that his training to ride at 90+ had a more positive effect on his fitness and preparing his body? Was 90 the magic number where the changes in fitness happened for him?

There are no simple, clear answers, as there are so many variables. In my next post, Part 3, I will look at one variable which may or may not play a role, (I haven't even investigated it fully yet, but believe I should). Stay tuned!

Coach Vance


Dan Cole said...

What is also striking is the correlation (or lack thereof) between power and bike time in 2011 and 2013, which were similar fast years.

Does this either imply a much more aero set up in 2011 to get same time on less power? Or more likely does it show the benefits of legal drafting in 2011 versus riding off the front and less drafting in 2013?

Jim Vance said...

Hard to say Dan, given the conditions being variable each year. Also, the dynamics of the race can be hard to determine and decipher. Also, could be based on aerodynamics and wind angle.