Of course there’s more to it than that; but, it’s been long known that exercise helps curtail symptoms associated with anxiety and depression.

Due to life changes that are devastating, I’m walking/running 8-12 miles a day and swimming 3-5. I still have severe anxiety (along with medication and therapy), but the days where I cannot get to the gym or out are FAR worse than those that I do.

30 mins of biking probably isn’t enough exercise to get to the threshold required to reduce your levels. While everyone is different, I need to hit the 45 min mark to feel any sort of benefit.

Fair point! 30 min is probably not enough. When I was able to maintain a routine similar to your own, the baseline was indeed better (and the days without were much worse). Best of luck in finding/maintaining the right balance for you.