Muscle stores carbohydrate as glycogen, and that store is small — roughly 1,600 kcal against fat stores measured in the tens of thousands. Endurance is largely a question of how fast that small tank drains and how fully it refills before the next session. Build a training week below and watch the tank move.
Seven days of glycogen
Inside the session
Build a training weekpick a day, then move the sliders
The carbohydrate slider is the whole day’s intake. The in-session slider does not add to it — it only decides how much of that same total arrives while the muscle is working. Timing changes the shape of the curve without changing the daily arithmetic.
Illustrative demonstrations of physiology built from round numbers and a simplified model. None of them is a plan, a target, or a recommendation for any particular person.
End of day — working muscle100% of normal
The session block and the day ledger are deliberately separate. Glycogen burned during the session came out of the stores, not out of the day’s intake — so it is not deducted twice. The surplus at the bottom of the ledger is what repays it. Every line is tappable.
What this page is not. It is a teaching model of average physiology, not medical or dietary advice, and not a fuelling plan for any individual — requirements vary with body size, training history, sex, altitude, heat, illness, medication, and conditions such as diabetes, where carbohydrate timing interacts directly with therapy. Those decisions belong with a qualified clinician or sports dietitian. No food is categorised anywhere here: glycogen is made from carbohydrate in grams, and grams are a physical quantity, not a verdict on a meal or a person.