Post-Exercise Carbohydrate Refeeding: How to Actually Restore Muscle Glycogen
Anyone training hard more than once a day, or racing on back-to-back days, eventually runs into the same question: how do you refill muscle glycogen fast enough to perform again? A 2025 narrative review in Sports Medicine, alongside the International Society of Sports Nutrition (ISSN) position stand on nutrient timing, lays out what the evidence actually supports — and it's more forgiving than the old "eat within 30 minutes or lose the gains" advice suggested.
Timing: the window matters most when recovery time is short
Glycogen resynthesis happens fastest in the hour or two right after exercise, then settles into a slower, steady pace over the following hours. According to the ISSN position stand, if rapid restoration of glycogen is required (less than 4 hours of recovery time), aggressive carbohydrate refeeding of 1.2 g/kg/h should be considered, with a preference for carbohydrate sources that have a high glycemic index (greater than 70). If the next session or competition is a day or more away, the urgency around timing largely disappears — total daily carbohydrate intake matters more than exactly when you eat it. Notably, some newer trial data cited in the review found that delaying carbohydrate intake by a few hours did not meaningfully impair glycogen resynthesis or molecular recovery signaling when total daily intake was adequate.
Amount: how much carbohydrate, and how often
- For rapid recovery (under 4 hours between sessions): roughly 1.0–1.2 g of carbohydrate per kg of body weight, per hour, for the first several hours after exercise.
- Carbohydrate with a high glycemic index (rice, potatoes, sports drinks, refined grains) resynthesizes glycogen faster than low-GI, high-fiber, or high-fat foods in this narrow window, largely because it's digested and absorbed more quickly.
- Full glycogen restoration after a depleting session generally takes 12–24 hours, even under ideal refeeding conditions — there is a ceiling on how fast the body can convert circulating glucose into stored glycogen.
Does protein help — and when
Adding protein to a carbohydrate-only recovery meal does not accelerate glycogen resynthesis when carbohydrate intake is already at the optimal 1.0–1.2 g/kg/h rate. But it becomes useful as an insurance strategy: when carbohydrate intake is suboptimal (roughly 0.8 g/kg/h or less), co-ingesting about 0.3–0.4 g/kg/h of protein alongside it can help close the gap and support glycogen resynthesis, while also aiding muscle repair. This matters in real-world settings — a busy tournament day, travel, or simply not having appetite for a large carbohydrate load — where hitting the top-end carbohydrate target isn't always practical.
Practical takeaways
- Racing or training again within 4 hours: aim for 1.0–1.2 g/kg of body weight in carbohydrate per hour, favoring high-glycemic-index sources, starting soon after exercise ends.
- Next session is a day or more away: focus on hitting total daily carbohydrate needs rather than exact timing.
- Can't eat enough carbohydrate right after training? Adding roughly 0.3–0.4 g/kg/h of protein can help make up for a lower carbohydrate intake.
- These are general, evidence-based guidelines for athletes and active individuals — not individualized medical or clinical nutrition advice. Anyone with diabetes, metabolic conditions, or other health concerns should consult a registered dietitian or physician before changing carbohydrate intake around exercise.
Helpful products
- Carbohydrate recovery drink mix — a convenient way to hit high-glycemic carbohydrate targets right after training.
- Digital food scale — useful for dialing in precise g/kg carbohydrate and protein targets.
Source: Sports Medicine (Springer) — Naderi et al. 2025; ISSN Position Stand
