With all of the electronic gadgets available to athletes these days, it is very easy to get deep into data.  Data definitely has it’s place in triathlon and training, but it is easy to overemphasize its importance, and even more so its accuracy.

Take a look at the data on my watch from the 40 minute run on the treadmill that I did today.

• The average Heart Rate and Maximum Heart Rate doesn’t appear to be extreme.
• Garmin is saying my workout had an aerobic ‘training effect’ of 3.6 and zero anaerobic benefit.
• My average cadence was 160 steps per minute

Based on this data, what kind of workout would you guess that I did?  If you are into data, I’m betting you guessed that I did something like a steady, easy pace Zone 2 run.  Looking at the maximum heart rate, you may have guessed I threw in a couple of faster intervals.

If that is what you guessed, then you were completely wrong.  I actually did a really hard workout.  I did the workout my coach calls ‘Treadhills’, that I wrote about last week.  

What is deceiving, is the interpretation that the watch made on training effect.  It estimated that my whole workout was at an aerobic or ‘easier’ intensity.  I am assuming it made this interpretation based on my average pace, which was slow for me.  It’s the heart rate data that tells a very different story. If you know one thing I didn’t tell you, my maximum heart rate, then you may have interpreted the workout a little differently.

My maximum heart rate is something like 174 bpm.  This means, that when I was running with a heart rate over about 162, I was above my lactate threshold.  That means I was working hard, unsustainably hard. When I was running up the steepest grades on the treadmill, my heart rate was up in that zone for several minutes.

I thought this data from my Garmin watch was quite interesting, because it didn’t reflect how I felt during the workout.  It didn’t reflect my perceived effort.  My perceived effort to get through this workout was something like 8 or 9 out of ten. 

Like I said… I worked very hard and I don’t need a watch to tell me that.