Metabolic Assessment – Take 2


March 8, 2013 by IowaTriBob

HR ZonesThis week I was able to get my second metabolic assessment done and it was definitely long overdue.

A metabolic assessment helps define your heart rate training zones, establishes your anaerobic threshold rate, and provides an understanding of your VO2 Max.  There are several different methods one can use to establish these numbers.

One method is to use one of the numerous (and highly inaccurate) formulas out there to calculate your maximum heart rate such as 220-age or 208-(0.7*age) and then take a percentage of your max.  I’ve been guilty of using this method before and found the results to be extremely disappointing.  Another way is to perform some self-administered field tests with your heart rate monitor and some perceived level of effort categories.  This type of test is somewhat subjective and can change from day to day.  The most accurate way is to perform a lab test that specifically measures your heart rate zones, lactic buildup, and thresholds.

I initially found a lab that was able to perform this type of testing looking at the USA Triathlon website for Certified Training and Performance Centers website.  In my area I found a lab center, Zoom Performance, at a nearby YMCA.  My last visit to Zoom was back in October of 2012 and I was very excited to see what type of improvements the same test would show 5 months later.

Zoom is able to perform Anaerobic Threshold (AT) and VO2 max testing through the use of a breathing mask to measure your levels of CO2.  This differs from Lactate Threshold (LT) testing which is performed by taking frequent blood samples.  For a more detailed discussion between Anaerobic Threshold (AT) and Lactate Threshold (LT) see

After a short warm-up, strapping on a breathing mask and heart rate monitor, plugging into a lab computer, I was off.  The test consisted of starting at a set speed of 5.0 mph (12:00 min/mile pace) and increasing by 0.3 mph every 60 seconds until you can’t continue any more.

Unlike the first time around, I felt great during the entire test and was able to really push myself as I’ve gotten more comfortable with being uncomfortable.  The results of the test were surprising.  My heart rate zones themselves didn’t really change from the first test.  For example, in October my anaerobic threshold was measured at 177 beats per minute.  My test this week showed an threshold of 179 beats per minute.  Statistically there isn’t any difference between the numbers.  So my HR zones continue to stack up as follows:

- Zone 1 (Aerobic recovery zone) – 116-146 beats per minute

- Zone 2 (endurance Aerobic zone) – 146-159 bpm

- Zone 3 (tempo aerobic/anaerobic zone) – 159-168 bpm

- Zone 4 (Anaerobic zone) – 168-179 bpm

- Zone 5 (red line or VO2 Anaerobic zone) – 179+ bpm

Where the improvements really jumped out was at the run pace within each zone.  During my first test with Zoom I hit my anaerobic threshold (AT) at a pace of 9:05 min/mile and stopped the test at my max heart rate with a pace of 8:40 min/mile.  My anaerobic threshold (AT) pace this time around was an outstanding 7:43 min/mile with a max HR pace of 6:59 min/mile.  That’s well over a minute per mile pace improvement.  These same improvements continued in all zones with my long run pace dropping almost 2 full minutes from ~12 min/mile down to ~ 10 min/mile.  In addition, my VO2 Max improved from 49 to 54 showing a greater aerobic capacity and endurance.  All in all – I’m extremely pleased with my progress as shown by the tests and in a relatively short period of time.  It’s great to validate some of the time trial testing with actual lab results.

If you haven’t looked into getting metabolic assessment with an Anaerobic Threshold (AT) or Lactate Threshold (LT) test, I’d highly recommend it as it takes the guesswork out of finding your zones and lets you focus on the training itself.  It’s also a lot of fun and some great motivation to see your improvements as your training progresses.

13 thoughts on “Metabolic Assessment – Take 2

  1. Chatter says:

    I would love to get one of these done but I think I need to get a deep tissue massage first. Sounds like things are progressing.

  2. IowaTriBob says:

    I am so with you there on the massage… I’ve had that on my list for some time. I just can’t seem to justify it, so I’ve been doing a lot of rolling and trying to convince myself its the same :-).

  3. Carrie says:

    Progress, progress, progress! :)

  4. David says:

    Sounds like the test told you what you had already learned in your Florida race, that you’ve dropped your times substantially!

    • IowaTriBob says:

      Thank you very much and being a very analytical guy this was great confirmation that the race wasn’t just a one time deal and something I can really use as a new baseline to continue building off of.

  5. Sandra says:

    Well, there you go! Congratulations on your continued move forward. And about the massage. Do it. I go in monthly (this month, I’m in three times–shoulder issues for poor posture/lack of proper stretching!)

  6. Thanks for sharing and good for you! This is something I would love to do, but haven’t bitten the bullet; I’ve always assumed it was expensive, but I’ll have to check with my tri shop sometime!

    • IowaTriBob says:

      Thank you as well! For me these have been really good as I’ve just gotten started and really help me pace myself as I start thinking about some longer distances and specific training zones this season. What I’m starting to learn is that once you have these established and start to workout in the specific zones you get a very good feeling on how your RPE (rate of perceived effort) is in relationship to your zones. I’m sure this is pretty basic for those that have been training for a while but for a new guy like myself its been a great tool to use.

  7. elisariva says:

    Great that your aerobic zone is so large! Your fitness is very strong. Great post.

    • IowaTriBob says:

      Thank you and I like these metabolic testing periods (and know you do yours frequently as well). Even if the improvements are small it shows how much your body positively responds to all the training.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Single-tracked Mind

Early nights and compression tights; trails and ales.

First Time Triathlete

All the info you need to get to the start line, the rest is up to you.

The Running Thriver

If I can do it, so can you!


A ridiculous man's struggle to become an Iron Man in 12 months

Stewart Park Triathlon

Competitive Triathlon - My Journey


My take on cycling!


sus·ing (soo’zing) n. an occurrence of life filtered through Susie’s perspective, spiced with a dash of wit and self-deprecation, and presented for entertainment's sake

Forty and Loving Fit

Husband, Father, and IT Pro training for triathlons on a 5 hour weekly budget.

Fitness and Frozen Grapes

Sweating, eating, and living my life as a young college graduate

Flatlander Tri Coaching

The home of anything and everything related to triathlon

Consulting Expert in Fitness, Health, Krav Maga, Personal Training and Nutrition

My journey to become an Ironman

Most people run a race to see who is fastest. I run a race to see who has the most guts.

10k Ray

Blog about Running & Triathlon in Ireland

Mom Racing Madness

When motherhood, a full-time career, and endurance athletics collide!


Old triathletes never die, they just transition....

The Shut Down Runner

Adventures in running...faster

Fat Guy to Tri Guy

My journey from being grossly over weight to completing an IRONMAN

heidi jo green

At the End of the Day it is Entirely up to You Who You Want to BE...

Triability Coaching

Professional Coaching for Endurance Athletes


Get every new post delivered to your Inbox.

Join 147 other followers

%d bloggers like this: