DopeyBadger
Imagathoner
- Joined
- Oct 15, 2015
- Messages
- 10,345
From Strava discussion:
"@canglim52 Wow!! And that makes a lot of sense. What was your starting VO2max? If I could gain 20-30% I'd be a very happy man
Is Garmin's LT Test close enough for a beginner like me? I have no clue where my LT is right now, I just know it's in the 170's."
Christian, my starting VO2max is a very loaded question. I have never had a lab based VO2max assessment. So all of my data is based on my Garmin 620/235's estimated value. It's important to understand how the Garmin calculates the VO2max. It uses age, HRmax, HR data, and pace at said HR data. Together it uses these values to calculate pace at %HR and then compare it to a dataset of 79 people with 2690 workouts. It uses that information to put you on a line of best fit for a VO2max estimation. But the HRmax data is critical for an accurate Garmin estimate. The error for the test subjects was about 3.5 on the VO2max score or roughly 5% from Garmin estimate to lab based assessment. But the accuracy of the HRmax data can make the error vary by as much as -9% to +7% dependent on how bad the HRmax is off from reality (again based on the 79 test subjects). So you could get a value of 50, but if your HRmax is wrong, then your real value could lie anywhere between 45 to 54. For the VO2max estimate, thats seems like a pretty wide estimate range, given a 45 VO2max estimates a marathon of 3:41 vs a 54 at 3:03. With that being said, if one were to never change their HRmax data then you could always compare to your previous values to see improvement. You may have the wrong value, but you could reasonably say your value went up by 10% (if 40 to 44 without adjusting HRmax between). So with that being said, I started running in June 2012. I received my Garmin 620 in Dec 2014 during my Dopey 2015 taper. My initial value was 48. I know from recent history that during a marathon taper my value drops by about 1-2 points. When I started my Hansons training in June 2015 it was 47/50. I can't be positive whether I did or did not change the HRmax during that time. I know I did consistently change it based on data I received during training runs (as well as the resting HR data). In October 2015, my last reading was a 53 before my chest strap stopped working. I ran with someone else's chest strap once in March 2016, and had a value of 54, but because of the extremely limited data set on one training run it can't be trusted fully. In Nov 2016, I got my Garmin 235 (now optical instead of chest strap). I changed my HRmax to 195 because that was the highest value I had seen my Garmin output that had a reasonable increase/decrease before and after it to suggest it might be real. My VO2max then climbed to as high as 61 (mid-December) around the same time I believe I hit my peak. As you know per my journal, I recently reassessed my HRmax based on my historical HR averages for certain race distances. I compared those values to the USATF and Jack Daniels table of %HRR and race distances to estimate my HRmax based on my personal performance. My races suggested that instead of 195, or 189 (220-age), my HRmax was probably between 170-180. So I changed my Garmin 235 to a HRmax of 180. My VO2max score steadily dropped from 61 down to 52 (partially because of this change and partially because of recovery time post-Dopey 2017). The score has started to rebound to 53-54 in the last week or so. Since there is a ton of wiggle room in the Garmin's estimate of VO2max I much prefer my method of assessing improvement by personally graphing my HR from training runs relative to the pace at which they were run. While the Garmin's VO2max value is dependent on HRmax, my system is not. As you know it has also allowed me to create a personalized race predicting calculator based on historical race HR data and a logarithmic curve on my last two weeks of HR training data. The best performance the calculator gave me was Oct 2015 when I finally broke 4 hours. I trained for 3:45 (set based on my HM PR at the beginning of training, even though I had yet to reach that race equivalency in a marathon). McMillan predicted 3:42 based on my recent HM only 6 weeks prior. My HR race prediction calculator said 3:38. I ran a 3:38. Although more recently the calculator hasn't been as accurate, although I believe external forces played roles in the inaccuracy of those (wind, injury, and Dopey other races). So if I were you and hadn't received an lab based VO2max you could do like I do and track HR vs pace personally. The change seen there will show you the improvement you're looking for. As you know I posted the picture on my run on Strava on 2/26/17 (since you follow my journal you're quite familiar with that graph). I have no idea on the accuracy of Garmin's LT test or how it is calculated for either a beginner or experienced person. However, I do know that the real sweet spot of training (if you believe Thomas Schwartz) is about 1-2% faster than LT. This pace zone allows you to train both VO2max and LT concurrently. Although it's really critical you know your LT and VO2max accurately because this is a very tight window. The typical workouts associated with this pace zone are 800m, 1000m, 1600m, 2000m, or 3000m repeats with resting intervals of 1 min per 1000m (hence 2000m is 2 min rest). The total distance of intervals should be between 4-6 miles but maintaining a balance of 6-8% of weekly mileage at this pace (known as Critical Velocity). Just two simple question leads to a wall of text. Typical Blaser response....
Here is the white paper from Garmin (link)
"@canglim52 Wow!! And that makes a lot of sense. What was your starting VO2max? If I could gain 20-30% I'd be a very happy man

Christian, my starting VO2max is a very loaded question. I have never had a lab based VO2max assessment. So all of my data is based on my Garmin 620/235's estimated value. It's important to understand how the Garmin calculates the VO2max. It uses age, HRmax, HR data, and pace at said HR data. Together it uses these values to calculate pace at %HR and then compare it to a dataset of 79 people with 2690 workouts. It uses that information to put you on a line of best fit for a VO2max estimation. But the HRmax data is critical for an accurate Garmin estimate. The error for the test subjects was about 3.5 on the VO2max score or roughly 5% from Garmin estimate to lab based assessment. But the accuracy of the HRmax data can make the error vary by as much as -9% to +7% dependent on how bad the HRmax is off from reality (again based on the 79 test subjects). So you could get a value of 50, but if your HRmax is wrong, then your real value could lie anywhere between 45 to 54. For the VO2max estimate, thats seems like a pretty wide estimate range, given a 45 VO2max estimates a marathon of 3:41 vs a 54 at 3:03. With that being said, if one were to never change their HRmax data then you could always compare to your previous values to see improvement. You may have the wrong value, but you could reasonably say your value went up by 10% (if 40 to 44 without adjusting HRmax between). So with that being said, I started running in June 2012. I received my Garmin 620 in Dec 2014 during my Dopey 2015 taper. My initial value was 48. I know from recent history that during a marathon taper my value drops by about 1-2 points. When I started my Hansons training in June 2015 it was 47/50. I can't be positive whether I did or did not change the HRmax during that time. I know I did consistently change it based on data I received during training runs (as well as the resting HR data). In October 2015, my last reading was a 53 before my chest strap stopped working. I ran with someone else's chest strap once in March 2016, and had a value of 54, but because of the extremely limited data set on one training run it can't be trusted fully. In Nov 2016, I got my Garmin 235 (now optical instead of chest strap). I changed my HRmax to 195 because that was the highest value I had seen my Garmin output that had a reasonable increase/decrease before and after it to suggest it might be real. My VO2max then climbed to as high as 61 (mid-December) around the same time I believe I hit my peak. As you know per my journal, I recently reassessed my HRmax based on my historical HR averages for certain race distances. I compared those values to the USATF and Jack Daniels table of %HRR and race distances to estimate my HRmax based on my personal performance. My races suggested that instead of 195, or 189 (220-age), my HRmax was probably between 170-180. So I changed my Garmin 235 to a HRmax of 180. My VO2max score steadily dropped from 61 down to 52 (partially because of this change and partially because of recovery time post-Dopey 2017). The score has started to rebound to 53-54 in the last week or so. Since there is a ton of wiggle room in the Garmin's estimate of VO2max I much prefer my method of assessing improvement by personally graphing my HR from training runs relative to the pace at which they were run. While the Garmin's VO2max value is dependent on HRmax, my system is not. As you know it has also allowed me to create a personalized race predicting calculator based on historical race HR data and a logarithmic curve on my last two weeks of HR training data. The best performance the calculator gave me was Oct 2015 when I finally broke 4 hours. I trained for 3:45 (set based on my HM PR at the beginning of training, even though I had yet to reach that race equivalency in a marathon). McMillan predicted 3:42 based on my recent HM only 6 weeks prior. My HR race prediction calculator said 3:38. I ran a 3:38. Although more recently the calculator hasn't been as accurate, although I believe external forces played roles in the inaccuracy of those (wind, injury, and Dopey other races). So if I were you and hadn't received an lab based VO2max you could do like I do and track HR vs pace personally. The change seen there will show you the improvement you're looking for. As you know I posted the picture on my run on Strava on 2/26/17 (since you follow my journal you're quite familiar with that graph). I have no idea on the accuracy of Garmin's LT test or how it is calculated for either a beginner or experienced person. However, I do know that the real sweet spot of training (if you believe Thomas Schwartz) is about 1-2% faster than LT. This pace zone allows you to train both VO2max and LT concurrently. Although it's really critical you know your LT and VO2max accurately because this is a very tight window. The typical workouts associated with this pace zone are 800m, 1000m, 1600m, 2000m, or 3000m repeats with resting intervals of 1 min per 1000m (hence 2000m is 2 min rest). The total distance of intervals should be between 4-6 miles but maintaining a balance of 6-8% of weekly mileage at this pace (known as Critical Velocity). Just two simple question leads to a wall of text. Typical Blaser response....

Here is the white paper from Garmin (link)