Crunch weeks at work show you how fast you can actually move. Remember that speed, then go back to a sane pace.

Emergency pace shows you a capacity you did not know about, and that is genuinely useful information. The mistake is concluding you should work that way permanently, because crunch borrows from rest, health and everything outside the task, and the bill comes later. Knowing your top speed is worth having. Living at it is not.

After an intense stretch, write down what you managed and how, since that is the part worth keeping. Then return to a pace you could hold for a year. Sprinting is a tool rather than a default setting.