There have been plenty of posts theorizing and breaking this down, so I'm sure I'm not covering any new ground here, but I have a couple of points to make that I specifically have not seen come across my dash that I wanted to mention. Put it under a cut because this got long. (whoops)
We first see Adrien running with Sublime in Sublimation and it seems like just an activity he's taken up, a new hobby. We get a deeper look at how he gets into this hobby at the end of Climatiqueen- where we see him walk past his house and pick up the pace, falling into a run and eventually bumping into Sublime, where voilá, a new friendship is born.
A lot of people have theorized that Adrien breaking into a run once he reaches the gates of his home symbolizes him running away from the oppression of the house that he shared with his father, symbolizes him running away from his life. Sublime even straight up asks him if he's running away. And I do believe that is true, in part. Just look at the angle that has been chosen to display the house as it comes into view- the house literally looks like Gabriel Agreste looking disapprovingly down the length of his nose at his son. It's looming over him ominously, a huge, imposing structure that suffocates the frame, taking up the majority of the space and making him seem small. This seems to perfectly encapsulate how Adrien is feeling about himself at this time in his life. Added to that he's probably got conflicting feelings and guilt over his father being gone. I wouldn't want to go home either.
But I think there's more to it than that.
Why Adrien starts running.
Adrien has just come from a very stressful and depressing day where, through no fault of his own or anyone else's, he's been made to feel marginalized and useless in contrast to all of his friends who seem to have something driving them, especially his extremely passionate, enthusiastic girlfriend. Despite her attempts to be helpful, all that's been demonstrated to him throughout the course of the day is that the only passion he has in his life- being a superhero, being Chat Noir- is something he can never do as Adrien Agreste, and it's something he can never share with anyone. This is a personal failure for him- he's letting Marinette down. Bad boyfriend move #1. Despite all her hard work and encouragement, he cannot settle on a passion that he can have as Adrien. He's made her inadvertently feel bad for having so many, so easily, and he can't even partake in the passion that he does have full time. His identity is literally and metaphorically fractured. Following all of that, having to return home to a house that no longer feels familiar or safe to him (for a variety of reasons) triggers a panic attack.
Physical exertion, specifically running, is a very common way to handle a panic attack. It is literally the flight response in 'fight or flight' manifesting during a period of high levels of stress- the feeling that you can't sit still, need to move, everything is building and you need an outlet to burn off that excess energy, until the adrenaline in your body normalizes.
Why Adrien keeps running.
Routine gives him something to focus on. Joining Sublime during her regimented training routine provides structure, the very thing that his entire life has consisted of and revolved around for 14 years, and has now been completely removed from his life, in a well-meaning attempt by the people who love him to encourage him to do what he wants to do for once.
This is terrifying.
The literal one-step-after-another aspect that running provides gives him a predetermined course to focus on. It's an automatic response; his body already knows what to do and there is no decision for him to make. It's something that he doesn't have to think about, something that's within his control. Additionally, the physical exercise itself provides endorphins, something he's sorely missing at this point in his life.
Ugh, Adrien. It's going to be a long, hard road for you, I'm afraid. 🥺💔
most of you are here to be motivated / find new methods of manifestation or simply thinking there is some hidden way you guys will find in this app to manifest instantly. But i downloaded it to post affirmations cuz i love typing affirmations so why not post them (also have free time) , while my main method of manifesting is subliminals . so the point is you guys should make a tumblr where you only post affirmations for fun , for yourself and that might also help others BECAUSE the key to manifesting your desire is detachment or diverting your attention to smt else i have realized this after making this tumblr, and the example is i was thinking about writing some shifting affirmations in my mind yesterday for this tumblr and when i fell asleep i shifted! + my self concept has gotten way better!