My triathlon season ended with the Tinman, but I did not want to shutdown entirely at that time. Instead, I decided to focus primarily on the Honolulu Marathon in December, and do the Honolulu Century Ride with as much training as I could fit in without jeopardizing my marathon training.
A few years ago I tried a hybrid approach, moving some of the long run time to the bike. The result was disappointing. Yes, long rides do contribute to aerobic efficiency and endurance, but not enough to muscular endurance. A marathon requires muscles, tendons and bones be developed to a high degree, and the only way to do that is to run. The workouts that are most important to the marathon are the long runs, done over many, many weeks, gradually building to 18 or 20 miles roughly three weeks from the race. Shifting those miles to the bike will have a negative impact on muscular endurance.
Between the Tinman and the Century Ride my weekends consisted of a long run on Saturday and a long bike on Sunday. I was building on a strong base, especially with all the work I put in preparing for Ironman 70.3 Hawaii, so it was simply a matter of doing a build to be ready to do 100 miles at a moderate pace.
On the first of these long rides I was going too hard. My notes remind me that I stopped about every ten miles and was exhausted at the finish. That reminded me of what many coaches have said, that the long run and long bike must be done at low intensity in order to train the body to burn fuel efficiently. A long training ride should not leave you totally depleted. Go too hard too long and your life outside training will suffer, and your workouts over the following days will be have to be drastically curtailed. Oh, and by the way, the older we get the more critical it is to get the intensity right.
My goal for the Century Ride was to do it at an average of zone 2, a lot like the bike segment of a full Ironman, and stay strong all day. No cramping, no wheels falling off. No limping back through Kahala, no crawling over Diamond Head. That first workout was already up in zone 2 and it nearly killed me, so I knew I had to really hold back and build up to it. I am pleased to say my plan worked.
The table above shows four of my build rides and the century ride. NP = normalized power, a calculated value similar to average power that represents the effort in watts for an equivalent ride done at a constant effort. NP is considered more useful for doing comparisons than average power. IF = intensity factor, where 1.0 is maximum sustainable one hour effort, also known as threshold, or lactate threshold. Longer events demand an IF well below 1. My Century Ride IF is a bit lower that I would have liked, but not too bad.
What this data shows is that after my initial over-cooked effort I pulled back and built back up to where I could go all day at an intensity that nearly killed me after 30 miles. Those long and slow rides really paid off.
As the ride got started I saw something similar to the start of the bike segment at Honu. My heart rate was through the roof. At Honu I had the swim to blame, but here it was all adrenaline. Normally my heart rate zone tracks closely with my power zone, although of course the power number dances up and down like a butterfly while the heart rate lags slowly behind, but from the start all the way to Kailua the two were split by at least one zone, as much as two at first. It looks really strange to be rolling slowing up Monsarrat at five miles an hour and see your heart rate in zone 4. All I could do was wait for it to settle down. A good reason why a power meter is so useful.
When a ride can be done at a steady, constant effort, NP and average power we be equal. The more variation in effort, the greater the difference. Another useful calculated data point is VI, Variability Index. A VI of 1.0 means NP = average power, regardless of what the power level was. Triathletes on a flat course strive for a VI as close to 1.0 as possible. The typical bunch start bike race demands considerable variation in effort, so expect to see a higher VI.
I extracted some data from each of the eight stages of the Century Ride:
|1 - Start to Sandy||121||85||397||0.71||1.42|
|2 - Sandy to Kailua||113||92||461||0.67||1.23|
|3 - Kailua to Kaneohe||103||80||282||0.61||1.29|
|4 - Kaneohe to Swanzy||95||83||197||0.56||1.14|
|5 - Swanzy to Kaneohe||93||81||374||0.56||1.15|
|6 - Kaneohe to Kailua||99||69||273||0.59||1.43|
|7 - Kailua to Hawaii Kai||101||76||342||0.60||1.33|
|8 - Hawaii Kai to Finish||91||69||362||0.54||1.32|
After we got settled down out on the highway I noticed that I felt good at power level 1.9, allowing it to rise up into the mid zone 2 for maneuvering or small climbs, higher for more pronounced climbs. My zone 1.9 works out to be around 88 watts. As you can see, the average power for most of the ride fell in right around that level. NP is a different story. NP was high during that first stage, and VI confirms it. After stage 1 things settled down a bit, but there was still a lot of variation. This is understandable given the crowded roads and variable terrain. Towards the end I could feel my quads complaining whenever I let my power drift too far into zone 2 for any length of time.
Take a look at stages 4 and 5, the same segment going in opposite directions. The data are identical except for a small increase in maximum power on the return, probably nothing more than pulling away from the aide station. This reveals that there was no wind out there; the speed and duration numbers confirm this.
The charts below show that I achieved my goal of riding on average in zone 2, with a nice, even distribution of effort. That I spent more time in power zone 1 (purple charts) is a reflection of the variability, and that my cruise power target was just slightly below zone 2.
The really good thing about this ride is that for the first time in a long time I was not a wreck towards the end. I was happy it was over, but I still had plenty left to ride home. The muscular endurance was there.