VO2max / aerobic fitness and seasonal allergies

Lietchi

So this is a stab in the dark, but perhaps someone here has a relevant experience.

The long story:
Based simply on the number of hours of exercise I do, I think I can call myself a runner
I've been running since November 2019. Very, very slowly at first (at the start of my weight loss). For a long time I kept things 'intuitive' and was making slow (but steady) progress. In October last year I felt my running performance was stagnating - I couldn't get past 7kph (8:34min per km; 4.35mph; 13:47min per mile). So I decided to start using Runalyze. I realised I had been undertraining, not pushing myself enough, and started making great progress by running more frequently and longer, which in turn increased my speed.
But in March my performance started stagnating again. I thought I was overtraining (I had gradually started to run almost daily and had increased my weekly mileage significantly) so I decreased my running for a few weeks to give my body a break.
Alas, when I started increasing my running again after the (relative) break, my performance even decreased. My VO2max as calculated by Runanalyze went down, as well as my Garmin's VO2max. And I've felt it too, it's like my lungs are having to work harder and they sometimes feel raw.

After having excluded overtraining as a cause, the only explanation I can think of is my seasonal allergies. I'm allergic to (amongst others) tree pollen which is a perfect fit for timing. I didn't notice a decrease in performance last year, but I wasn't training as hard then and my allergies are relatively new anyway (less than 5 years) so perhaps still evolving. I take an antihistamine daily, but it doesn't seem to make much difference.

TL;DR: my running performance/fitness level has decreased lately. Could seasonal allergies be to blame?

NorthCascades

Sometimes it's good to have a quick recap, forgive me for being Captain Obvious.

When you run, you're using your muscles to propel yourself forward, they need oxygen to make most of their fuel, which is why your heart rate goes up (to supply oxygenated blood). Your limit isn't your muscles, it's how much oxygen you can bring them. VO2max is a measure of how much oxygen your body can deliver. As you exercise more, your body adapts in several ways, many of them to deliver more oxygen. Your heart gets stronger, and also larger to improve stroke volume, you develop more blood plasma to carry more O2, etc.

A lot of these adaptations are short term and stop happening when your exercise load goes down. If you're running less due to seasonal allergies, that could be why. If you're having more trouble breathing, that could also be why.

BrianSharpe

Here's an article I found on the topic...

https://runnersworld.com/uk/health/a765365/hay-fever-all-you-need-to-know/

You may also want to try what Galen Rupp did..... as pollen counts were insanely high and he has asthma Galen wore a mask at the 2011 USA Track & Field Championships (and won). I understand that hs mask was made by

mu2sportsmask.com/

I haven't used one myself so I can't comment on how effective they are or whether they restrict your breathing at all.