Hour 24
Glycogen Nearly Gone
One full day in. Your body is running on stored fuel. The hard part is mostly behind you.
What's Happening
Liver glycogen is nearly exhausted. Muscle glycogen is preserved (the body protects it). Ketone production is substantial. Gluconeogenesis — making glucose from amino acids and glycerol — has ramped up to maintain essential blood sugar.
How You're Feeling
Hunger comes in waves but is manageable. Mental focus often improves as the brain adapts to ketones. The body is running efficiently on fat. Sleep quality on a 24-hour fast can be surprisingly good — the metabolic calm supports it.