If you're at all like me, there's the manic periods of development, where things get done... and there are the lulls. What do you like to do in those lulls? Do you have a bin of fun work shit to do? Do you watch videos? Touch grass? Socialize?
I normally try and do "fun" work. This largely depends on how autonomous your job is. I was a PhD student doing research for a company and I received very little oversight for 3 years.
The supervision I did receive was great though. They understood needing to take a break and slow down. At those point I would generally read papers, watch PyData talks (highly recommend them, like inspirational ted talks for data people), or contribute to open source to learn about new tools or design paradigms.