The night before a long workout

Eat something you already know you digest. A chicken and rice plate, yogurt and oats, or turkey and a potato. Not the hottest new stew, and not a huge unplanned takeout you have never tried before a long ride or run.

Include carbohydrate. Protein alone is not the fuel for the session. Drink enough that you are not starting thirsty, unless a clinician has you on a fluid limit.

Afterward, eat a real meal when you can. A shake is a backup, described in food vs shakes.

Nothing here is an individualized fueling plan. Long training days is the kitchen version of "decide earlier."