hit the wall

/HH IH1 T DH AH0 W AO0 L/
verb
  1. 1

    To experience sudden fatigue as a result of glycogen depletion, e.g. when cycling.

    syn:bonk
  2. 2

    (pickup community) Of a woman: to lose her physical attractiveness through growing older.

Synonyms

Source: https://en.wiktionary.org/wiki/hit%20the%20wall