VO2 max decreasing

[Runizoomi]

I’ve been running 5/6 times a week for the past couple of years. However, the last month or so I’ve seen my stats going in the opposite direction.

I’m running 100 miles a month, and at the start of lockdown my stats were looking good, my heart rate was relatively low and my VO2 max increased to 46.

Since then, everything has been the opposite. Today was a steady not too strenuous 5 miles, my heart rate averaged 167 and my VO2 max decreased to 40! It’s not been that low since I started running!

I try and mix up my runs and do intervals once a week. I’m getting so demotivated by my stats, as they don’t seem to reflect how my run feels.

I should add that I’m 48 and use a Garmin.

Any advice would be greatly received

I am not a runner. I measure VO2 max on a treadmill about once a month just to monitor it. Have steadily increased over the last few years and very proud of myself.

No way to measure it during lockdown and I did keep up with exercise daily but in all honestly not nearly as much HIIT cardio as I would normally do. I tested when the gyms opened again. Over lockdown mine went from 48 to 41.

I don't know how often you measure. Lockdown was/is stressful and the weather (at least here) today was hot and humid. Not sure if that has an effect but I would have thought so. The only advice I can give is to say that if the run feels good then maybe it's just a weird anomaly reading. If readings keep going the wrong way then I personally would be looking at more high intensity work (as I am currently doing for myself).

Are you doing more short runs ? I remember reading that Garmin Vo2 max favoured longer runs.

Btw I’d love to have your problem ...I’m 53 and a slow runner and even when training for a half only managed to get mine to 33 😢

Thanks for your responses.

I run on average 5 miles outside but on a treadmill I tend to do longer runs, 10K plus. I have been doing less treadmill runs though and more outside ones, so maybe not getting the longer distances in.

I have wondered if it’s to do with the weather as have found it so muggy recently and much prefer rainy colder runs.

I probably just need to ignore it and go with feel, it’s just so frustrating 😬

As a start, your Garmin is not measuring V02 max, it is predicting it based on a number of things. The only way to actually measure it is in a lab with proper gas analysis equipment, and a properly painful maximal effort to total exhaustion. HR response can be affected by lots of things, including heat, hormones, fatigue, blood volume and composition, illness, etc. You could just be going through fighting off something, being a bit more tired, in the heat, and that would make your heart work a bit harder, increasing the average, and making the Garmin algorithm think your VO2 is lower.

How does Garmin estimate? I've had my vo2max measured twice with full breathing apparatus. I know there are other ways to benchmark fitness like heart rate recovery.

Thank you, that all makes sense.

I’m just a bit frustrated at my perceived fitness, when I thought that it should be improving, heart rate lowering etc. I know that weather and time of the month has a lot to do with it, I’m just a bit disappointed.

Before running I never thought I was competitive, but I’m so competitive with myself!

Could be the heat...you would expect a much higher HR for the same pace in hot weather. That's a very good VO2 max for your age btw!

Mine has gone down this week from 52 to 50 (which for an almost 40 year old I'm chuffed with!) and Garmin says my training status has changed from 'productive' to 'over reaching', I've not changed anything and am doing my usual weekly mileage. I read in their help information that you would expect it to decline in warmer weather, but other than that I'm none the wiser either!!

PlugUgly1980 That’s amazing!
My score has gone back up slightly, so I’m putting it down to the weather, hormones and not mixing my runs up enough. I did an interval session this morning and my figures all look a bit better.
I’m hoping that come the cooler months my stats will look amazing 😉

Mine has also gone down for no apparent reason. I also use a Garmin. I blame the heat!