V02 MAX and Lactate threshold pace in 935 vs Fenix 3

If you ever start/stop your watch (i.e. track workouts) it seems to greatly affect these stats -- at least on the fenix3 and 920XT. I wonder if they've finally corrected for it on the 935?

I think it also depends on what the watch determines as your max heart rate which then sets your zones, T.E. and other figures which I'm assuming would include LT and VO2. Lastly (and I'm still new to the 935 so don't quote me on this), it might be possible that you're getting different readings from the wrist HR vs. the more accurate chest HRM's such as the HRM-Tri?

This is all just my take on it -- would love to hear from anyone able to chime in on it more definitively...

Matt

Well setting max HR is crucial. I would not just rely on what the watch "determines" it is but enter a value you have actually got to in the last few months in some sort of maximal effort. Hill reps often yield the highest HRs.

if your VO2 Max has "dropped" 4 points then which figure gives the more realistic race predictions? Are you also saying you think you are as fit now as in March?

And as Matt notes which source is your HR coming from?

Thanks for responses

Thanks for the comments.

I take the Garmin VO2 Max based Race estimates with a grain of salt as the predicted times are not what I have achieved in racing. I can run a 20 minute 5k but Garmin at 54 says I can do a 19 (or maybe I am just to soft to push through hard enough to need my potential!)
I run with the blue chest HRM Tri so not an issue of bad optical data.
Max HR I have hard set at 182 as otherwise winter runs with chest HRM can get wacky readings if I forget to moisten contacts.
I believe am fitter or as fit as March.
VO2 max moved to 54 today so at least heading in right direction.

Will be interesting to see where the numbers end up at the end of the month.
I received my forerunner on April 17 so just under two weeks to have a full set of data.

I reckon they have updated the algorithms. My 935 is 2 points below the 735 on VO2Max and I'm arguably fitter now. Still I think that's a good thing as going by the race predictor it's still a bit on the optimistic side!

CW

Sounds like it is certainly in the ballpark. Even despite what CW notes, the predictions are notoriously optimistic although really that means that the VO2 Max estimates are bit high. I usually reckon the race predictions for 3 VO2 Max "points" less than you are at are more on the money. It is allrelative though and even if your max HR is "wrong" (how did you get to 182 BTW?) then changes in VO2 Max up or down ought to tell you something.

Hm, I really think my max HR might have (significantly?) decreased over the last three years. Maybe I should adept the value.
What would be the effect? Will VO2max decrease when I reduce my max HR? Might be realistic.

Sounds like it is certainly in the ballpark. Even despite what CW notes, the predictions are notoriously optimistic although really that means that the VO2 Max estimates are bit high. I usually reckon the race predictions for 3 VO2 Max "points" less than you are at are more on the money. It is allrelative though and even if your max HR is "wrong" (how did you get to 182 BTW?) then changes in VO2 Max up or down ought to tell you something.

I use 182 Max HR as I hit 183 at the end of my last 5k in October. Ran a half last weekend and hit 180 in the last kick but tired legs were the issue there.

I hit peaks of 186 in 2011 and 185 in 2013 (which is still the value I use...)
The highest HR have been some 182s over the years (but last time 2015).
Yesterday I did 8x400m R-pace (Daniels) but haven't seen more than 169.

Well, I have a 5k in two weeks, maybe I will adjust based on that result.

I recently lowered my HRMax value to 3bpm higher than what I hit at the end of a PR 5k after that my VO2Max dropped 2 points after a couple of regular runs and the 5k time in the Race Predictor now is a few seconds off what I ran in that race.

The marathon time is still optimistic but that's more to training than it being a physiological unreality, but that's pretty common.

I hit peaks of 186 in 2011 and 185 in 2013 (which is still the value I use...)
The highest HR have been some 182s over the years (but last time 2015).
Yesterday I did 8x400m R-pace (Daniels) but haven't seen more than 169.

Well, I have a 5k in two weeks, maybe I will adjust based on that result.

From experience using this feature over the years, it is best to lower your max HR to a more recent figure. A few years ago I hit 170. Of late 162 has been the highest so got it to 162 at moment.

Of course if you want to flatter yourself and see high VO2 Max then set your max HR very high but it isn't a "competition"...