After years of floundering, I think I'm finally getting it: You get energy by spending it. The fuel tank metaphor is completely misleading. The body supplies energy to meet demand. The tank *expands* if you use a lot of fuel. In other words, biology is fundamentally antifragile

Placing heavy demands on a machine grinds it down. Biology, on the other hand, grows and strengthens in response to challenges, as long as they're not completely overwhelming

The machine metaphor has many good uses, but on the subject of bodily and mental energy, it's actively harmful: it makes you conclude from a lack of energy that you need to save what little you have; from tiredness that you need to rest. This leads into a shrinking feedback loop

Spending energy on something is like submitting a request to your biology to make that kind of thing a little easier next time. Correspondingly, not spending energy on anything is effectively like a request to make life in general harder

Ofc, you need to replenish with sleep and moments of rest, but the latter need only be a few minutes to catch your breath, and different parts of the bodymind gets to rest in different activities, e.g. the mind can rest during physical exercise, muscles during meditation, etc

So in theory, if you have a well developed energy system, from having gradually increased your level of activity over time (so as not to overwhelm a bodymind that may or may not be addicted to rest and recreation), you shouldn't need much downtime besides sleep

"What does not kill me makes me stronger" is one way to express this antifragility point, but it is phrased too dramatically: it makes me think of passively befallen illness and accidents, rather than active effort. Perhaps better: "What does not overwhelm me makes me stronger"

This is not a big issue for most people, bc they have a lot of external demands and responsibilities, like work and kids. I have more free time than most, and I've spent it on rest, thinking it would help me get my strength back. Instead, it got me stuck in the shrinking loop

In other words, my depression seems to have been caused or at least seriously exacerbated by a misleading metaphor

Save your strength if you want to lose it

It's certainly true on the scale of days and months, but at least sometimes, I find that activity can build felt energy capacity in a matter of minutes https://twitter.com/metaphorician/status/1529408035692724224

This makes me think I could really use a morning ritual designed specifically to work like a kind of energetic on-ramp. The morning walk that was so popular around these parts on Twitter a few months ago might serve this purpose in addition to the circadian rhythm anchoring one