Sunday, January 12, 2020

Training Log Analysis Part Two: The Heart Rate

As noted in my first Training Log Analysis post, I do pay attention to my heart rate. In this post, I’m going to digress to a very technical discussion of my easy training and anaerobic threshold heart rates. I apologize to anyone who finds this boring but promise there is a bit of emotion mixed in and more to come in future posts. Largely suffice it to say, this post is for my own benefit but anyone who likes analyzing data or wants to know about my secret workouts might find this interesting.

There are certainly a lot of ways to calculate what “levels” or “% max heart rate” these training zones correspond to so I’ve included a table with the best descriptors I’ve ever found.


This table didn’t include the Levels. I put these in based on my previous understanding of training levels. It should also be noted that “20% slower than marathon” in Level 1 is irrelevant to skiing when snow conditions dictate effort and pace. I don’t agree with the heart rate of Level 1 being 70-78% and other resources cite 60-72% which I think better correlates to an “easy” effort. I will use that lower percentage for my analysis below.

It’s been a few years since I’ve tried to find my maximum heart rate, but it’s a bit lower than predicted models. If using the formula 220-age = max heart rate, and I’m 34 now, that would give me 186. My heart rate has never been that high (since I started using a heart rate monitor almost 10 years ago), hence I’m guessing my max heart rate is closer to the upper 170s. An analysis of why my max heart rate is lower than average is way beyond this blog. For simplicity sake and calculating my Level 1 and 3 heart rate zones, we’ll say my max heart rate is 178.

I’m going to glance over Level 2 because much of the literature recommends training either at Level 1 or at Level 3 or higher. As I’ve been doing more intervals, I tend to either train hard or easy and much less in the“gray zone” that is Level 2.


Level 1


Level 1 training should be 60-72% of max heart rate which works out to be 107-128 for me. So how do I do staying in Level 1 for the easy workouts?

Here’s a variety of training modalities and some “easy” days:


-2.5 hour Afton skate rollerski: average heart rate 124

-1.75 hour neighborhood classic rollerski: average heart rate 109

-1.3 hour easy run: average heart rate 126

-1.5 hour skate ski at Battle Creek w/ 1,283 feet of elevation change: average heart rate 128*

-3 hour ski at Hyland: average heart rate 124

-2 hour classic at Lake Elmo: average heart rate 115



* Note: this is when I know I’ve “made it” when I can ski easy under this terrain on a day following a couple hard 5 km races.


Overall I stay within heart rate targets for Level 1. My neighborhood classic skis often feel quite easy and not at all taxing. But that’s the point, this Level is also called “recovery” and it should feel easy. That’s the goal of these workouts. Even my average heart rate of 128 for my hilly Battle Creek ski felt easy.

An easy street/adventure ski in Bemidji over the holidays when it snowed too much. The skinny boards don't do so well without grooming:) Yes, this snow was up to my knees! Photo: Erik

Level 3


Level 3 is somewhere between 78-92% of max heart rate based on the model above with 85% smack in the middle. This corresponds to heart rates of 139-164 and 151 for me.

Over the past couple years I’ve honed in on the Level 3 workouts. I started doing these for running training and realized their immense value and so began incorporating these into my ski training last year. Yes, I know, pretty crazy that I made it so far without doing dedicated Level 3 workouts as a marathon ski racer!

First, I’m going to analyze the above predicated Level 3 heart rate by looking at some racing data. I’m going to pull data from three different benchmarking races.

The first race is the 2019 skate Birkie. I did well for myself at this race and was definitely “in the zone” for just about exactly 3 hours. For that race my average heart rate was 153. Now, it’s always easy to say in hindsight that I could have gone harder but in brief, I took it slightly conservative to OO, then really began pushing. With 25 km to go or so, I was tired. If I remove that hindsight, I know I gave it everything I had. So around that heart rate, or slightly higher, is a good goal for my anaerobic threshold (Level 3) intervals.

My Birkie 2019 heart rate profile. I like that it progressively goes up towards the very end.


The second race is the 2019 classic Mora Vasaloppet. This race is almost pancake flat and primarily double poling which tends to be an efficient technique for me, at least at cruising speeds. My average heart race for that race, over 2.75 hours, was 149. This is quite similar in terms of time and average heart rate to the Birkie. As I look back on this race, which I skied mostly by myself, it’s easy to think I wasn’t working hard, but my heart rate shows otherwise. So here again is a good target for my Level 3 intervals.

My Mora Vasaloppet 2019 heart rate graph. Here you can see it starts out higher when I was skiing with others. I'm pretty sure at the point it drops off was the last time I was skiing with anyone.


The third race is a 27 km running race around Lake Bemidji. I aced the pacing of this race to the point that the last half mile felt like I was finishing a 5 km. Over 2 hours and 12 minutes my average heart rate was 155. Surely this felt like the absolute max of my aerobic threshold (and about the same time as an elite male marathon runner) and so this should workout to be about 85% of my max heart.

85% of 178 (my presumed max heart rate above) is 151 so either I’m racing above my aerobic threshold (which based on how I felt near the finish and afterwards is quite likely) or my max heart rate is actually higher than I can get it to go (more on that next post).

I've posted this photo before but I love that my face is in complete agony. I guess this is what happens when you push way into the anaerobic threshold and don't win! Erik, all smiles, said he wants to do this race again because he had more to give. I on the other hand, put it all out there and somewhat doubt I could even repeat this performance, let alone better it. Photo: the mother-in-law:)


The data on my slightly shorter races, such as those that take the duration of a running 10 mile or ½ marathon, in the 1.5 hour range, only reveal slightly average higher heart rates such as 158 in the Hamsterbeiner in 2017 when the Birkie was cancelled.

Given all this, it seems I tend to race longer races with heart rates in the 150s. Hence, I’m targeting the higher range of the 150s for my threshold Level 3 intervals.

In the summer we did a classic rollerski workout of 5 x 6-8 minute intervals. My average heart rates for these intervals were 141, 146, 148, 150, and 150. This is a nice progression of Level 3 build up. When I first looked at these heart rates I wasn’t too impressed. But after comparing them to my average heart rate for last year’s Mora Vasaloppet, I see they are on par.

I was curious to see how this would compare to a similar running workout. The rollerski workout started out quite flat where I often flail and don’t have the technique to go as fast as I’d like and then ends with an uphill so I was interested to see how more even pacing on flatter terrain would be running. So I did 5 x 1 mile (just under 8 min/mile pacing) with average heart rates of 146, 154, 160, 161, and 161. Again this showed a nice progression but these were about 10 beats per minute higher than my classic rollerski workout. This was likely because it was my first running interval workout in 2+ months and therefore I was easily able to push harder running.

Now that I’m on snow I’ve done a couple classic and skate threshold workouts. Given that I’m targeting the Mora Vasaloppet Classic, which is predominantly double poling, I’ve focused my classic thresholds on flatter terrain. The first one was 4 x 15 minutes with average heart rates of 142, 142, 141, and 138. Yikes, well below my target in the 150s. The conditions weren’t ideal but I thought I had overcome that. My second classic threshold went similarly with 5 x 15 minutes. I even decreased my rest from 5 minutes to 3 minutes. Despite this my average heart rates were 132, 136, 136, 136, and 131 (last one lower perhaps because I changed up the course?). Again, way below my target heart rate in the 150s. Not sure why this is other than I’m not pushing hard enough, maybe because I’ve been doing these solo or because it’s not a race. I’m giving myself credit for at least trying these and hoping since last year was my first year doing these, it will give me a step up and at least it got my muscles sore. Now with one more of these before race season begins in February, we’ll see if I can hit my target heart rates.

My heart rate graph from my classic threshold workout at Elm Creek


So far I’ve done two skate threshold workouts (overall I’ve fallen behind on my goal of alternating classic and skate threshold workouts every week). The first one was part of a Vakava practice back on November 20th. This means I had people to push me. We did 3 x 15 minutes and my average heart rates were 149, 149, and 159- a bit low on the first two and then hit the third one well within target. On my second skate threshold workout a month later on December 22nd, I did 4 x 15 minutes with average heart rates of 152, 152, 151, and 148. Obviously not ideal that my last one was lower than the previous ones. These should really build. Not terrible, but based on these heart rates, I could do a tad better.


My heart rate graph from the second skate threshold.


In summary, my goal heart rate for Level 3 should be in the high 150s. I can hit this easily running, greatly struggle with double poling, and am close with skate skiing. In the end, just attempting these workouts is great training and likely to benefit me.

Stay tuned for my next post on Level 4 analysis!

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