Tuesday, January 20, 2015

Threshold Heart Rate

I have been using Training Peaks for 13 months now.

Training Peaks is an online site that allows me to upload my cycling and running workouts from my Garmin watch and pour over the data (pace, elevation, distance etc).

It also allows me to enter workouts manually (like CoreFit and swimming) and keeps track of time spent doing each one, total distance and calories burned among other things.

I have not signed up for the full version yet because the free one has been meeting my needs so far. and I really like it.

A few weeks ago I started getting interested in measuring my heart rate during workouts (something I tend to do every few years until I stop caring and go back to just looking at pace and distance).

Two Saturdays ago I ran 10k with my heart rate monitor on. I uploaded it, checked out all the data, noted my heart rate and then hopped in the shower. I came out of the shower to find an email from Training Peaks in my inbox congratulating me on my new threshold heart rate of 162.

My what?!

The email told me to log into Training Peaks and change my threshold heart rate to 162. It also explained what a threshold heart rate is. They used a bit too much jargon but I think I understood it to mean that it was the heart rate that I could sustain for long periods of activity such as running. The idea seems to be that increasing my threshold heart rate is a good thing because it means that I am able to sustain a higher (harder) level of activity than I used to be able to sustain.

Does that make sense?

So I dutifully logged in and changed my number to 162.

This past Saturday, I headed out to run 10-11k but ended up running 13k because it was so lovely out. Again, I wore my heart rate monitor. Again, I uploaded the data, checked it out and then hopped in the shower. And again I received an email from Training Peaks congratulating me on my new threshold heart rate of 167.

So now I'm extra curious. I have not been using my heart rate monitor with Training Peaks until now so I had no idea about any of this.

My next research will be to figure out if there is a threshold heart rate that I should be aiming for. Because, let's face it, for all I know a number of 167 is completely laughable. I have nothing to compare it to and only know that increasing the number is positive because the emails I'm getting from Training Peaks include the word "congratulations!" at the beginning.

My questions:
- is there a threshold heart rate I should be aiming for or is it different for everyone?
- are there different threshold heart rates for different sports? Because my heart rate on the bike never gets as high as my heart rate on a run and it's even lower during CoreFit and Tabata classes. There doesn't seem to be a distinction in Training Peaks - there is just one threshold heart rate.

1 comment:

  1. Here's the easiest way to understand lactate threshold heart rate (LTHR). It's the heart rate where you start to work harder but don't typically go much faster. It's the effort where your muscles build up waste products (lactate) as fast as they can get rid of them. Any harder and you start to get the burn and huffing and puffing as your body starts supplementing the effort with energy from the anaerobic system.

    The surest way to know your LTHR is with a blood test using a device similar to a glucose meter (except it measures blood lactate). This is rarely done outside of exercise labs, though. Most of the time you can find your LTHR one of two ways: run a very hard effort for a prescribed time with a HR monitor and put the average into a formula or do a progression run and see where your speed and HR stop correlating. I'm not sure which TrainingPeaks is doing.

    Given this description, you can see that LTHR is independent of activity. This is one of the great things about it. When you're racing triathlon, you can use the same heart rate targets (more or less) on the bike and run. The fact that you see different heart rates when you do different sports is complex; reasons include different levels of muscle adaptation (conditioning), whether an activity is more aerobic or anaerobic, etc. Plus, most people run too hard. :-)

    Finally, everyone's LTHR is different. You can certainly train it upward--and this is the goal of interval work--but each person's ideal LTHR is unique.