This kind of implies that you're crunching and then 'recovering'. That may or may not be something you have any control over - there's a lot that goes into creating an unsustainable 'sprint', and probably 99.8% of it is not related to actual developers or code - but ideally you would be using these 'lulls' to try to pull stuff out of the next crunch so maybe it won't hurt so bad.

In reality, if I'm coming off of a bad crunch, I do anything I can do to avoid burnout. Sometimes that's 'fun' backlog items or research for future features or something else I'm excited about, sometimes it's studying for certs, sometimes it's cutting slack (@cianuro@programming.dev watching Netflix feels familiar!). But again - whatever it takes to recharge my batteries and feel less bitter and shitty.

The most 'sure' sign that I'm coming off a crunch, though, is that I start reinforcing work/life boundaries. "It's 5p and I'm logging off and I'm not going to think about work shit willingly until tomorrow."