Impactful? Definitely. Most impactful? I doubt it.

When my energy levels were highest in my life, it was because every day I had something I genuinely looked forward to. I was frequently working on projects that allowed me to "be in the flow". I would often think about how to further progress with these projects even when I wasn't actively working on them, and it wasn't because I worried about not meeting the deadline. I was confident in my ability to finish the projects on time. It was out of passion.

The advice here is definitely valuable and should not be disregarded, but I think it is invaluable to find something that you genuinely enjoy doing and to do it regularly. This is way easier said than done and I unfortunately don't have much advice on how to find something like this, but I promise that it will be worth the effort.