What is the lowest possible fitness age?

Mine is currently 20 at a VO2max of 56.

I have been up at a VO2max of 60 but cannot seem to remember seeing any ”age” lower than 20.

Ahh, my is only 44, so then I think we may be safe to assume that 20 is the lowest possible age :-)

Thanks for the feedback!

I've noticed that my fitness age can vary by a few years for the same VO2 max

That's because VO2max has actually a decimal that is not shown. If you watch carefully the position on on the VO2max Gauge can also vary slightly at the same number. 

When it comes to VO2max it seems to be a bit sensitive to differences in activities.

I have experienced an increase of 2 points based on a few interval runs on track - and then loose it on the next longer run on the road.

I’m quite sure I could «trick» it up again by just do some shorter track intervals  track.

As I often do intervals on the treadmill and longer run outdoor it seems like it think I have a lower VO2max score.

Not sure why, it might be because I’m quite heavy, so the longer runs often starts out with a +3 to +5 but ends out at -2 to -10. 

Anyway, all ower the VO2max score seems to be a resonable good indicator, you just have to know about it’s weeknesses and manipulation points. Like now when I seem to have found a nice and steady rythm to my training with a good balance of workouts and rest, the VO2max, my fitness age, my timings, my feeling all give me the dame indications. I’m getting into better shape.

It’s been a long periode with ups and downs, mostly - I think - because I getting to eager and pushes to hard when it’s OK, and then gets injuries, fatique and looses all progress instead of getting a steady buildup. Trying to train more steady and beeing more pationed now. I actually has more restdays now than in a long time, and it seens to work.

I’ll guess I’ll see in a couple of month if this is a good strategy.

agree on it being 20 as the lowest. mine has been that for a while with a V02 max of 55 - 56

I’m a sixteen year old girl and I have VO2max of 56 and my fitness age is also 20 so I’m guessing it can’t go lower than that

I've recorded VO2 as high as 65 and it was still a fitness age of 20.

Noticed today for the first time the fitness age is 20. Being 69, it seems of minor meaning tot be 20. I do not like the prospect of starting working again for 45 years.

Researching this.  I'm 61 and I'm told fitness age is 20. Not sure that is correct.  But your post had me laughing out loud.