VO2 max

First make sure that the watch has all your personal details correct: age, wieght, height, RHR, max heart rate etc.
On the other hand a 6:25 min/km pace is not very impressive. If this is all you can do, then perhaps the VO2max estimation is not that much off.
A hard reset will hardly help. All it can do is the VO2max estimation will start all over again, meaning that at the beginning it will be even more inaccurate than you current estimation.

Indeed that is a huge improvement and I would not focus on VO2 max. VO2 max is at least 50% genetically determined so you can only make a certain amount of impact by training. The range of VO2 max is quite wide in top international athletes and many perform at the top of their sport without necessarily having the highest VO2 Max. The best way to impact VO2 is by including intervals in your training run at a pace that is roughly the fastest pace you can maintain for 8 mins. Include sessions at that pace in one or two of your runs and I believe that you will see an impact on your VO2 - you only need 2-5 minutes worth at that pace a couple of times a week. In general you will see greater benefits by varied intensity in runs and varied distances so that you are constantly challenging your body to adjust to different stimuli. Also if you look at your VO2 max for a 30 year old male (don't know your age) it gives a predicted race time of 56:02 for a 10K race - so that is what you could expect to achieve with the right training based upon your "current" VO2. Bear in mind also that you have lost a huge amount of weight in 2 months and your body is still adjusting. Just carry on and perhaps mix up your training runs a bit and I'm sure you'll continue to see improvements.

JSRUNNER_, that makes absolute sense. Just wanted to add that the predicted race time should not be age dependent.
45 km/week is quite good, however, your speed is very slow. Maybe you're more the Ultra-guy (rather than the 10k-guy).

The most straightforward way to further boost your VO2max and speed: Lose another 25 kg - given nothing else changes, this will up your VO2max by 20% to 42; and as you already lost 25kg once, you know how to do it ;) (I admit I have no idea how hard that is; the most I ever lost were 5 kg in 6 months)

But as already pointed out, there are many other ways to improve (running economy, lactate threshold, ...)

Congratulations on your amazing weight loss and your commitment to fitness and running! Don't get discouraged by the numbers your watch is throwing at you. I think the improvements in your running (distance and speed) are awesome! I lost 65 pounds 3 years ago and started running so I know how hard it is. I just finished my first marathon 2 weeks ago. I am not the fastest but they gave me a medal at the finish line anyway! Good job!

Forgot to say, I would NOT do a hard reset for this. I think the watch needs more time to "know" you. I actually think that my 935 overestimates my VO2 max and I've had mine since March 31st. I am a 51 y.o. female who was an overweight couch potato for most of my life. Now I run 3-4 days a week, my 5k PR is 30:45, 10k is 1:05, half is 2:24 and my marathon was finished in 6:03. Certainly not a star athlete, and yet my watch tells me my VO2 max is 40 which is in the mid to high excellent range and it tells me my fitness age is 20. I mean, come on! Really?? So, take it with a grain of salt.

First off congrats on the weight loss and improving pace. Don't let how fast any of the stats coming from the watch improve because the rate of change will slow no matter what.

Weight, HR, and pace are the main factors the watch uses to come up with Vo2Max score. Vo2Max is measured in milliliters per kilogram per minute (ml/kg/m) so if you're losing weight faster than you're speeding up, at the same HR, then the Vo2Max score will go up more slowly than if you were at a stable weight.

The other thing to consider is that it is an indirect measurement and is using HR in place of equipment directly measuring the gases you breathe out. So simple things like the temperature and how well you've eaten and slept in the last 24-48 hours can affect a single result. Which is why it's best to focus on the trend rather than what it is and how much/fast it's moving.

Well done on your progress. As for VO2 Max/race predictions https://cicerunner.wordpress.com/2014/07/11/garmin-fr620-race-times-from-vo2-max/ is a table I remember we discussed some years ago. Judging by your 11 K pace suggests you could do 5K all out perhaps bit under 30 mins and a 10K in about an hour. Although values are not given for 35 VO2 Max (can you see them on the watch?) looks like would be about that.

Also VO2 Max estimates are heavily dependent on setting an accurate max HR on the watch and not necessarily using the default 220-Age estimation. What have you got there?

TonyMR,

impressive, you haven’t told us how old you are...

loosing 25kg in 9 weeks puts a huge stress on your body which will take its tolll.

Considering that 1kg fat delivers about 7000kcal, which is the energy need for about 2,5 days the lost weight equals to about calorie amount for 62,5 days or your 9 weeks if it all had been fat. As this is not realistic unless you ate no food at all, most of the weight loss in addition to fat will be water and muscle. Your body already switched into the ‚starving‘ mode, buring as little calories as possible.

Bottomline this is extremly challenging for your body and the jo-jo effect is waiting. VO2max is the last thing I‘d worry about. Hope you consulted your doc before...

Thank you all for the advice and the congratulations.
Actually, it is pretty easy to loose weight... eat less and be more active... :)
I took it a bit extreme with the less eating, but meanwhile I'm used to not eating much.
The hardest part is your body and mind playing games with you and trying to make you eat.
Well, I had enough of being fat for the last five years (before I was ok) and decided that I had to get my life back on track before the age of 50!
I'm 49 (July). When I looked at most of my colleagues at work (who are all 50+) I saw that they were too fat and getting all kind of physical and mental illnesses...
It was or following their way of life (and get sick sooner or later) or making a drastic change in the way I live.
I chose the latter.
Nine weeks later, I look and feel like a different person.
I even inspired some of my colleagues who are now also on a diet and started running.
I still want to lose 10kg, but that's just a matter of weeks (I try to lose 2 kg per week).
Anyway, thanks a lot for the explanation about VO2max!
I think I run too much on distance and not enough on speed/interval.
I do uphill and downhill running, but no specific interval training so far.
That's because my most important reason for running is weight loss.
Running is also a kind of meditation. I get in a flow and try to stay in the moment.

Anyway, thx to y'all for answering.

TonyMR,

impressive, you haven’t told us how old you are...

loosing 25kg in 9 weeks puts a huge stress on your body which will take its tolll.

Considering that 1kg fat delivers about 7000kcal, which is the energy need for about 2,5 days the lost weight equals to about calorie amount for 62,5 days or your 9 weeks if it all had been fat. As this is not realistic unless you ate no food at all, most of the weight loss in addition to fat will be water and muscle. Your body already switched into the ‚starving‘ mode, buring as little calories as possible.

Bottomline this is extremly challenging for your body and the jo-jo effect is waiting. VO2max is the last thing I‘d worry about. Hope you consulted your doc before...

Hi Jumanji,

thx for your advice.

I know about the jojo effect and the starving mode :)
I visit my doctor every month and he congratulated me with the progress so far.
I have a special scale that measures body fat, but also muscle mass, visceral fat, water percentage, etc (Tanita scale).
I know that a part of my weight loss is muscle, but that's limited since I do muscle training every day.
My water percentage has even gone up compared to the first day I started.

Even my colleagues laughed with me in the beginning using the jojo effect as a way to try to demotivate me...

But nine weeks later, they are all in admiration...

I eat very healthy, lots of fruit and veggies, no potatoes, no pasta, some whole grain bread, lots of water, almost no sugar...
I feel very energetic and even have enough energy to go for a run in the dark at 6 o'clock in the morning.
I wake up every morning at 4 o'clock and it takes me 1,5 hours to get to work.
But the most important thing is my mental health / strength.
That's because I put the final result in my head all the time, even when my body or mind try to play games with me :)

Anyway, only the future will tell if I get a jojo effect or not. But it looks good so far :))))