> After all, we were made to move around, it's entirely plausible that many biological processes in our bodies just don't work well while sedentary and our anxiety is trying to tell us that.

Muscle contractions function as the heart for our second circulatory system.

https://en.wikipedia.org/wiki/Lymphatic_system

A few animals have an actual second heart for that, but we don't—we have to move to make it work well.