Home FitnessRunning Get Your Fundas Right – VO2 Max, Race Predictor, Garmin and Training

Get Your Fundas Right – VO2 Max, Race Predictor, Garmin and Training

by Alfredo Miranda

This blog does not pretend to be a full article about VO2 Max Training and the likes. The aim is to clarify some points in this topic because several runners are getting confused due to a superficial knowledge of it.


VO2 Max

I have heard several times messages like “It is in the Tempo runs where you improve your VO2 Max”. This comes in many cases from checking how our Garmin shows us the VO2 Max. Let’s have a look at the results in my case in the last month:

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It can be seen that there are 3 picks. The number 1 corresponds to a day when I did 8km at 5:45 pace, with 2km near 5:30, the number 2 was a day that I did 8km at 6:00 with 2km at 5:45; the number 3 was a stronger one, when I did 4km at 4:30 pace. Otherwise, the rest of the days the pace has been 6:30-45, only last week is going down to 6:15. Conclusion: whenever I do a faster run my VO2 Max goes up, so the more runs like this the better… then: “It is in the Tempo runs where you improve your VO2 Max” is true !!!!!


Let’s explain the “fundas”- What is “VO2 Max”?


The endurance sport occurs mostly in the “aerobic zone”, it is the zone of the exercises where we use mainly oxygen for the generation of energy, it is an area of medium intensity a relatively comfortable pace. If we increase the pace, then we enter into the “anaerobic zone” where no oxygen is used (or very little). But we can’t sustain this for very long: if you try to run a marathon in the anaerobic zone… you will hit the famous “Wall”!! “Aerobic zone” is synonymous of “Oxygen”: the more Oxygen you can handle… the stronger will be your aerobic zone: and the faster you can run a marathon or any other endurance sport.

Then, “VO2 Max” is a number which tells you the maximum amount of Oxygen your body is able to handle. The higher the value, the higher the speed you can keep in aerobic zone and therefore the better your performance. For sprinters this value is irrelevant. Sprinters go in anaerobic so it is not important.

Who is the runner with higher VO2 Max? Well, there is no information available on the internet about Eliud Kipchoge, however in this article (click here) they estimate as high as 89.7 . But… out of the info available… Kilian Jornet has 92 !!!!!


Can the VO2 Max be improved?

Yes, we all can improve our VO2 Max. If we are talking about handling more Oxygen… then we have to run in the area where we are handling Oxygen: sounds logical, doesn’t it?

As sown in the graphic: We have to run most of the time in the aerobic area with few runs in the tempo zone, close to the anaerobic zone but without crossing it. Doing this for several weeks, we will move the limit of the aerobic zone, making it bigger so that we are able to run faster and still remain in the aerobic zone.

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If you go back to my numbers, I mentioned 3 runs, the total distance adds 20 km. The total mileage for May was 190km.

Now, you may ask: “Then, Why the VO2 Max goes up only in the Tempo runs?”.  THIS IS THE DECEIVING POINT !!!!

The key point is that Garmin needs a tough run to measure properly the VO2 Max !!! In those tempo runs you are actually measuring your VO2 Max in a better way than in the slow runs.  What is happening here is that during your slow runs you are improving your VO2 Max, but your Garmin is not able to detect it. Only when you do a tempo run and your Heart Rate goes up, then your real VO2 Max comes to the surface and your Garmin can catch it !!!

If you don’t yet believe me… take a relook  at the graph of the VO2 Max readings, see those picks and think: “The Oxygen is taken by the blood from the lungs to the muscles pumped by the heart… How can this mechanism change up and down from one day to the next?”


Race Predictor

Now, another source of misunderstanding: the Race Predictor. If we go back to the numbers of the VO2 Max, the point 2 corresponds to a reading of 48, and that day (which is also the same reading as the day before the point 3) my Garmin was telling me:

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The day I did the run number 3, with those 4 km at pace of 4:30… The VO2 Max moved to 49 !!!! And the new numbers were:

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Now, you tell me: “Do you really think that because of a 4km run a bit faster, now I can run a Marathon 4 minutes faster?”

I can tell you NO WAY !!!!!! In fact, I can assure you that right now… I can’t run a marathon at all !!!! Not in 3:23, not in 6 hours !!!! (moreover, right now I can’t run any of those distances 5K, 10K or HM in the given numbers).

These numbers are based on the VO2 Max, and represent the capability of your body, better: the capability of your metabolism considering its capacity to handle Oxygen. But your metabolism is not everything you need to run a marathon: You need to train that metabolism to perform at that level for the required time, you need a strong muscles; proper hydration; adequate nutrition that your body can assimilate; proper mental strength to handle the race, etc, etc, etc… And to put all this in place takes months, as you already know.

Going back to those professionals: Kilian Jornet has higher VO2 Max than Eliud Kipchoge, but this does not mean that he can break the Marathon world record. He will need to train very hard following a very specific training to come close to Kipchoge’s timings.

Then, what are these numbers good for? If they don’t represent the reality?

Well, they may not be the reality today, but it could be after sometime and proper training. What your Garmin is telling you is not what you can do tomorrow… but what you can do after some months of proper training !!!

You can use these numbers to select your next training plan. In my case, I know I can’t run tomorrow a marathon in 3:23:16, but…. As soon as I finish writing this blog… I will look for a 3:23:00 training plan for next winter !!!!!

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Sanjeev Chhabra June 11, 2019 - 10:21 am

Thank you, Tanya and Alfie for bringing alive this term that Garmin kept throwing at me and Ihad no idea about. Also loved to expand my knowledge about aerobic and anearobic respiration.
If there is a piece written by Alfie, you can be sire no details will be left to assumption.

Tanya Agarwal July 6, 2019 - 12:19 am

So true, Sanjeev. Alfredo stays the master of running science.

Kapil June 13, 2019 - 5:55 pm

Excellent Article, lot of misconceptions were clear.
Thanks for sharing


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