Friday, September 1, 2023

Getting Enough Zone 2 Time

My heart rate during a recent 110 minute ride on my Cañada route. The space between the two white, horizontal lines is Zone 2. This is my best effort to date at completing that ride in Zone 2.


In my last post, I described the belief of many coaches and exercise scientists that I should be riding 80% of my rides at an easy pace, heart rate Zones 1 and 2, and that 20% of my rides should include appropriate amounts of riding faster, in heart rate Zones 3, 4, and 5, a rule called the 80:20 rule. For example, I ride five days a week and according to this 80:20 rule, four of those rides should be limited  to Zones 1 and 2 and one should contain more intense riding in Zones 3, 4, and 5. If you have not read my last post, you might find it worth reading first.

Do my recent rides conform to the 80:20 rule? These days, my riding is almost entirely on two "routes", my Cañada route and rides on the trainer I set up in my bedroom. It is useful to divide my rides on the Cañada route into three groups: slow, medium, and fast. The ride whose heart rate profile is shown at the top of this post is an example of a slow ride. These rides stay fairly well within Zone 2. If I don't pay any attention to how fast I am riding and just ride the way that feels most natural, that is a medium ride and is about 50% in Zone 2 and 50% in Zone 3. A heart rate profile of such a ride is shown in my previous post. Finally, if I really push in order to set a personal best on that route, that is a fast ride. Below is a heart rate profile of such a ride:

In this figure, the three white, horizontal lines delineate both Zone 2 and Zone 3. Very little of this ride is in Zone 2, much of it is in Zone 3, and a significant amount extends into Zone 4 with even a little bit in Zone 5. 

Similarly, I have found three different kinds of rides I am willing to do on my trainer. (The main determinant of what I will willing to do on the trainer is that it is quite boring so ride length is limited to 30 minutes.) I can ride for 30 minutes in Zone 1, a ride I find fairly pleasant and which I often do as a warmup for the resistance training my physical therapist has prescribed for my bad back. Alternatively, I can do a 30 minute ride in Zone 2. This is less fun. On the road, I find Zone 2 quite easy but on the trainer it is a push and so the 30 minutes seems even longer. Finally, I can do a version of the Gillen et al. High Intensity Interval Workout that I talk about so much. That includes two minutes total (6 x 20 second intervals) at the high end of Zone 5 and 28 minutes at Zone 1. Interestingly, this is less boring and thus less of a slog than the Zone 2 ride but not as pleasant than the Zone 1 ride. The first two rides count towards the 80% in the 80:20 rule and the third counts towards the 20%. I will discuss how I count the different Cañada rides below.

Which of the above rides should I be riding? To answer that question, I have to go into more detail on the 80:20 rule. That rule is based on some assumptions. One assumption is that, on average, a high intensity (20%) ride lasts about half as long as a low intensity (80%) ride (e.g. in minutes, the 80:20 rule becomes the 90:10 rule.) Second, a high intensity ride consists of warmup before the high intensity intervals, recovery periods between the high intensity intervals, and a cool down after the high intensity intervals, so only a fraction of the minutes of that ride are done at high intensity, the rest are done at low intensity. The fraction of high and low intensity depends on many things, importantly, on how "high" the "high" intensity is. All high intensity rides have warmup and cool down periods of 15 minutes each but the number of intervals, length of the intervals, and recovery time between the intervals varies significantly. As detailed above, a Zone 5 ride may consist of only 10% Zone 5 minutes compared to a Zone 3 ride which can consist of as much as 75% Zone 3 minutes.

There is one more complication, any rides I do have to be rides I can actually do on the roads around where I live. One big aspect of this is the hills that I am always complaining about. It is much easier to ride up hills at high Intensity (Zones 3, 4, and 5) and much harder to do so at low Intensity (Zones 1 and 2). Thus, it is unfortunate that the Cañada route has its biggest hills at the beginning and the end of the ride just where I should be warming up and cooling down.

Given all the above, how do my "slow, medium, and fast" Cañada rides fit into an 80:20 compliant training schedule? The slow rides are very good Zone 2 rides, contributing to the 80% side of the 80:20 rule. Both the medium and fast versions of the Cañada ride share the problem of lacking the 15 minutes of warm up and cool down they should have. This could be fixed in the medium ride by being more attentive to when I ride slow and when I ride fast. The fast version of the ride doesn't leave room for warmup and cool down, I would have to do a slower version of that ride to fix that. Assuming I did both those things, the medium version of that ride would be a 75 minute Zone 3 ride with an extra 15 minutes of Zone 2 riding and the fast ride would become a 90 minute Zone 3 ride.

Assuming I will be doing two trainer rides and three Cañada rides a week, what kinds of schedules could I put together? To satisfy the 80:20 rule, all schedules will consist of four rides in Zones 1 or 2 and one ride at higher intensity. All trainer rides will be 30 minutes long, a Zone 2 Cañada ride will be 110 minutes long and a Zone 3 Cañada ride will be 90 minutes long. One schedule would consist of three Zone 2 Cañada rides, one Zone 1 trainer ride, and one interval session on the trainer. On a minute basis, this would be 92% Zone 1 + Zone 2 and 8% at high intensity, a bit low on the minutes of high intensity riding. Also, the coach I follow, Coach Hughes, thinks that, for a rider like me, Zone 3 riding is important and this schedule lacks any Zone 3 riding. A different schedule would be two Trainer rides in Zone 1, two Cañada rides ridden slow to be in Zone 2, and one Cañada ride ridden at medium speed so as to contain  a 75 minute Zone 3 ride. On a minute basis, this would be 79% Zone 1 and Zone 2 and 21% at intensities higher than Zone 2, much higher than the 10% suggested by Dr. Seiler. On the other hand, I don't think Dr. Seiler's 90:10 minute rule contemplated Zone 3 riding, I think it assumed that the higher intensity riding would be in Zones 4 or 5. Since a Zone 3 ride is longer in minutes than a Zone 5 ride, it may be OK that my Zone 3 ride is more than 10% of my total riding. Finally, for reasons I hope to discuss in a future post, I hope to reintroduce some longer Zone 2 rides into my schedule which would have the effect on improving that ratio.

As my final point I would like to talk about how I have been actually riding and why that has deviated so far from the ideal described above. As I blogged about a few months ago, beginning at the end of May of this year, my general feeling of wellbeing declined significantly. The first impact of that is that I went four days with no bike rides at all. As a reaction to that, I figured anything was better than nothing so began doing short, easy rides on my trainer. That lasted for about five weeks at which point I began feeling a bit better and restarted rides on the road, mostly on my Cañada route. Although the Load of a Zone 2 (slow) ride on that route is less than that of a mixed (medium)  Zone 2 + Zone 3 ride, it does take more attention and focus, so in the interest of doing the best I could, I decided to "just ride" which resulted in way more Zone 3 riding than the 80:20 rule would recommend. I would argue that, all things considered, this was a reasonable course of behavior, that these were good reasons for ignoring the 80:20 rule. However, there were also some bad reasons that contributed to this behavior that I think are worth discussing.

The first bad reason for going above Zone 2 during my Cañada rides had to do with the bike I use for those rides, my Bianchi Volpe, my bike with the lowest gears and my only bike with a "triple", three gears on the front. Triples are known for poor shifting which is why they are so rare despite the wider range of gears they provide. Thus, shifting through the nine gears on the back is much more convenient than shifting through the three on the front so the way I tend to use the gears on this bike is to leave the front gear set, depending on the general geography of the road (uphill, downhill, flat) and to do most of my minute to minute adjusting using the rear gears. I have to also admit that there is an element of ego as well, I take pride in the fact that I can easily make it up the long Jefferson climb at the end of the ride in the middle gear in the front, that I don't "need" to shift into the low gear. However, once I realized I was doing this and started shifting into that low gear for the Jefferson climb, I was able to maintain my heart rate in Zone 2 during that climb, something I had not been able to do before.

The second bad reason for going above Zone 2 is similarly related to ego. I have recently switched to using Load rather than Minutes as the metric for the amount of riding I have been doing. I did that primarily to avoid generating more Load than I realized as a result of riding too fast, but very quickly it became a competitive game to see how high a Load score I could get for the week. The best way to increase that Load score was to ride my Cañada rides faster. Rather than using the Load measurement as intended, to help me stick to a well designed training plan, I was using it as a goal resulting in it doing the opposite of what it was supposed to do. Having realized that, I am much more careful about how I think about my weekly Load score.

I have one more Cañada ride scheduled for this week. The previous two have been quite good Zone 2 rides, giving me the opportunity to experiment with this third ride as a better Zone 3 ride, one with 15 minutes of warmup at the beginning and 15 minutes of cool down at the end. Stay tuned to see how I do.