Recovery nutrition
Evidence: moderate
Rapid refuelling only matters when the next hard session is hours away; otherwise total daily carbohydrate and protein do the work, and the “anabolic window” is far wider than once claimed.
Not medical advice
This is a general knowledge base, not medical or dietary advice. If you are injured, unwell or weighing up a supplement or a change to your diet, speak to a doctor, physiotherapist or registered dietitian who knows your situation.
After a hard or long session two jobs remain: replace the glycogen the muscles burned, and supply the protein to repair and adapt. How urgent either is depends almost entirely on when you next need to perform. For fuelling the session itself see in-race carbohydrate, and for the protein detail see protein and recovery.
Glycogen resynthesis: timing matters only when the clock is tight
Rapid refuelling matters in one situation: a second hard session within roughly the next 8 to 24 hours, such as a double day or a multi-day race. There, take carbohydrate early and at a high rate, around 1.0 to 1.2 g per kg of body mass per hour for the first few hours, eaten in frequent small feeds rather than one large meal (Kerksick et al. 2017). The muscle takes up glucose fastest in the period immediately after exercise, so when the recovery window is short, getting carbohydrate in promptly genuinely speeds the rebuild.
When you have a day or more before the next demanding session, this urgency disappears. Muscle glycogen refills fully within about 24 hours given enough carbohydrate, and what governs that is total daily intake, not the timing of the first meal (Burke et al. 2011). For most runners, most of the time, the recovery-shake-within-minutes ritual is solving a problem they do not have; see daily carbohydrate and energy for the figures that actually matter.
Protein for repair, and the overstated window
For repair and adaptation, aim for roughly 0.3 g of protein per kg in the post-session meal, about 20 to 40 g, which is near the dose that maximises the muscle-protein-synthesis response per serving (Aragon & Schoenfeld 2013). The narrow 30-to-60-minute “anabolic window” is largely a myth: a meal eaten before training leaves amino acids circulating well into recovery, so immediate post-workout protein is often redundant, and the practical window spans several hours (Aragon & Schoenfeld 2013). Across the day, total protein matters more than its timing; apparent timing effects mostly vanish once daily intake is equated (Schoenfeld, Aragon & Krieger 2013). Spread roughly 1.6 g/kg/day across several meals and the window takes care of itself; see protein and recovery.
Rehydration: replace more than you lost, with sodium
To restore fluid balance you must drink more than you sweated out, because some is lost as urine; replacing about 125 to 150% of the fluid deficit over the hours after exercise is the practical target. Volume alone is not enough: unless the drink carries enough sodium, the surplus is simply passed as urine and you stay in deficit (Shirreffs et al. 1996). After a short or easy run the deficit is trivial and the next meal handles it; the deliberate replace-with-sodium approach is for large losses after long or hot efforts. See hydration and electrolytes for why salt is the lever here and why overdrinking is the real danger.
Co-ingesting carbohydrate and protein
Adding protein to a recovery carbohydrate feed gives no extra glycogen benefit once carbohydrate is already at the ~1.0 to 1.2 g/kg/h rate (Kerksick et al. 2017). The case for combining them is when carbohydrate intake is sub-optimal: protein then partly compensates for the shortfall in glycogen resynthesis, and you cover repair at the same time. A mixed meal does both jobs.
Fuelling during the session
Carbohydrate taken during a session aids recovery as well as within-session performance, though by a modest, secondary route. Fuelling the work sustains blood glucose, which spares muscle glycogen and blunts the body’s stress response: carbohydrate during prolonged intensive exercise attenuates the cortisol and growth-hormone rise and leaves fewer perturbations in immune-cell counts and inflammatory activity than placebo (Nieman 1998). A 2024 systematic review confirms the hormonal part: pre- and mid-exercise carbohydrate reliably attenuates the cortisol rise, with a smaller effect on adrenaline (Christ et al. 2024). High intake during very long events may also lower post-race muscle-damage markers (Viribay et al. 2020). Fuelling for the work therefore leaves a smaller deficit to recover from. The effect is modest, though, and the original immune work flagged that its clinical significance is unproven (Nieman 1998). It is a useful side-benefit of fuelling sessions you should fuel anyway, not a substitute for meeting total daily carbohydrate and protein needs, which remain the main drivers of recovery.