2012 Boulder 70.3 Bike Split

2012 vs 2011 Bike Splits - Fairly Consistent Riding

I decided to compare my 2012 bike split to my 2011 bike split from this race to see how they stacked up, given that the times were nearly identical (~1 minute faster in 2012).  In 2011, I entered this race with a measured functional threshold power (FTP) of 315 watts; in 2012, it was 325 watts.  At the same level of intensity (intensity factor, or IF), my split should have been faster, but probably more than a minute so.

As you will see from the graphs below, the difference was that I rode the 2012 race at a lower overall FTP and a lower IF than the 2011 race.  However, my total split remained essentially the same.  In a race where I actually got to do the run, this would have been a pretty good execution of the bike leg.

The Data

The 2012 data is shown in the graph below (click the picture or caption to view a larger version).  Before I get into a real comparison of the data, I should note that in both races, I used the following equipment:

• 2009 QR Lucero Lite TT bike
• SRAM red components
• Quarq SRAM S975 cranks (53/39)
• Zipp 808 wheels
• Sidi T2 shoes

Equipment in 2012 that differed from 2011 includes:

• Giro Advantage 2 aero helmet vs. Bell Sweep road helmet in 2011
• SRAM Red 11-26 cassette vs SRAM 11-23 in 2011
• Garmin Edge 800 vs CycleOps Joule 2.0 in 2011
• Garmin HR Strap vs no HR strap in 2011

Using the Garmin was nice, because I would break down the race into custom-length sections via the "auto-lap" function.  This would allow me to monitor my performance over specific portions of the course.  I chose to break the race into quarters (14 miles each).

My goal was to maintain my normalized power (NP) over each 14 mile section at about 260 watts, while also trying to maintain average power (AP) at about the same level.  The ratio of NP to FTP is the IF, while the ratio of NP to AP is called the "variability index" (VI), which measures how steady your effort is over the span of the measured interval.  A low VI (close to 1.0) indicates you road very steady without too many discrete hard surges or easy efforts.  This can be important in a triathlon, because too many short, hard efforts can really tire you out, and can have a huge impact on one's ability to run well off the bike.

As you can see from the data, I was about 5-6 watts higher than my goal effort on the first loop of the course.  The 1st and 2nd 14-mile segments show that my NP=266 watts, with IF=0.82 (i.e., 82% of FTP) and VI=1.03.  Not too bad.

Lap 2 of the bike was not bad either.  My power dropped about 11 watts to 255.  Less than I wanted, but still very, very close to IF=0.80.  In that last 14 mile stretch, I had a very hard time staying in the aero position.  I did a lot of bike racing this year, so I was not on my triathlon bike nearly as much.  Consequently, I hadn't adapted well to the aero position for significant periods of time.  That is probably the reason that my last 14 mile split was about 3 minutes slower than both of the previous 2, yet power output remained fairly close to the other splits.

All-in-all, this was a pretty good bike split.  The overall numbers were right where I wanted them, with NP=260 watts, IF=0.80 and VI=1.02.  Average speed for this bike split was 24.04 mph for a total time of 2:19:53 unofficial (officially, 2:20:01, still right at 24 mph)

2012 Ironman Boulder 70.3 Bike Split

On the 2011 graph, the auto lap functionality was not available (or I didn't think about how to do it with the Joule), so I had to re-create as best I could after the fact using the available data.  The total distance measured is different from the 2012 graph because the Joule measures speed/distance based on a speed sensor and magnet placed on the wheel.  If your calibration isn't spot on, the measured distance will not be even as accurate as GPS.

The 2011 race was very similar to 2012 overall, but there were some distinct differences.  First, I knew I wasn't doing the run that year, so, I started out really trying to blaze the bike, because I didn't need to save anything for the run.  Consequently, if you look at the first segment, you'll see that my NP=282 watts.  Based on my FTP at the time (215 watts) that's an IF=0.87, or 87% of my FTP.  That's VERY hard for a half Ironman split.  In the second 14 miles, I realized I couldn't keep that up for the entire race, and you'll see that I backed off considerably to NP=270 watts (IF=0.83), which was still pretty high, but still manageable.  VI for both segments was great (1.01) as I rode very steady.

On the second loop, you'll see I suffered a bit from that hard first segment, as my NP dropped even further to 253 watts (IF=0.78) in the first 14 miles of Loop 2, and even further to 250 watts (IF=0.77) in the last 14 miles of the bike leg.  This lap shows what can happen when you go out too hard.  Imagine how I might have felt at mile 9 of the run, had I had to run after that?

Overall numbers for the 2011 bike split were a bit higher than 2012.  NP=264 watts for all 56 miles, which is an IF=0.81 (remember, my FTP was 10 watts lower in 2011).  Average speed was just under 24 mph as I finished the bike leg in 2:20:50.

2011 Ironman Boulder 70.3 Bike Split

Takeaways

• Raising FTP is good (duh!).
• Riding a consistent effort is much better than riding too hard out of the gate and fading at the end.
• Speed will come over the course of the ride.  This is not a bike race.
• Get a comfortable fit and learn to stay aero for the entire length of the race.  There's a lot of free speed there without additional effort.

Have I said anything we don't already know?