Why Am I So Hungry the Day After a Long Run?
The same pattern turns up in almost every runner I work with. Sunday's long run goes well, appetite stays oddly quiet that evening, and then Monday becomes a day of opening the fridge every forty minutes. They usually ask whether something's wrong. Usually nothing is. The body is collecting a debt from the day before.
The short answer
Hunger the day after a long run is your body asking to refill the energy and glycogen you used, because appetite often lags behind expenditure, sometimes by a day or more. Eat more carbohydrate and protein on long-run days and the day after. If you're hungry all the time, you're likely under-eating across the whole week.
Quick Overview
Why am I so hungry the day after a long run?
You're hungry because you're still short on energy from the run. A rough rule is that running costs about one calorie per kilogram of bodyweight per kilometre. On that rule, a 60kg (132lb) runner doing 25km burns around 1,500 calories on top of a normal day's needs. That's close to a whole extra day of meals for some people.
Glycogen is the second part. A two-hour run takes a large share of the carbohydrate stored in your muscles and liver. Refilling those stores takes steady carbohydrate across the following meals. When they're low, hunger is one of the plainest signals your body has.
Most runners also eat less than they think on the long-run day itself. A small breakfast before an early start, a late brunch, a lighter dinner because they "aren't that hungry". On Monday the body is making up for Sunday.
Why wasn't I hungry straight after the run?
Long or hard exercise briefly turns appetite down. Acylated ghrelin, the hormone that drives hunger, drops during and after exercise. PYY and GLP-1, the hormones linked to fullness, rise (Schubert et al., Sports Medicine, 2014). In the hours after a session, people generally don't eat back what they burned (Schubert et al., Appetite, 2013).
The research is less tidy about what happens next. On the day after a 90-minute run, one study found no rise in hunger hormones or in how hungry people said they felt (King et al., Physiology & Behavior, 2015). Those studies mostly use young men and a single session. Over weeks of training, eating seems to catch up with what you've burned only partially and slowly. So the day-after hunger is real, but there isn't a precise clock on it. For some runners it arrives on Monday. For others it builds over the week.
The practical point: don't wait for appetite to tell you how much to eat on a long-run day, because it shows up late.
How much more should you eat on long-run days?
Plan for more carbohydrate on the long-run day and the day after, rather than dropping straight back to rest-day eating. The sports nutrition position statement links daily carbohydrate to training load. That's 5–7g per kg of bodyweight a day for about an hour of moderate exercise, and 6–10g per kg for one to three hours of moderate-to-high-intensity endurance work (Thomas et al., J Acad Nutr Diet, 2016).
For a 60kg runner, a long-run day in that higher band means roughly 360–600g of carbohydrate. That sounds like a lot until you count it out. Three generous meals built around rice, roti, pasta, oats or potatoes, plus two snacks, gets most runners there. The day after, aiming somewhere in the 5–7g/kg range is more realistic than going right back to a light day. The daily carbohydrate guide covers how to scale this across a training week.
Protein matters too. For most runners I recommend 1.2–1.6g per kg of bodyweight a day, which sits inside the 1.2–2.0g range in the sports nutrition position statement (Thomas et al., J Acad Nutr Diet, 2016). Spread it across meals rather than eating it in one or two sittings. You don't need to rush it after the run. Your next normal meal does the job.
What should you eat the day after a long run?
Eat bigger, planned meals with a carbohydrate base and a protein source, instead of grazing all day. Grazing usually feels like eating a lot and adds up to less than you needed.
A day that works might look like this. For breakfast, poha with peanuts and a bowl of curd, or oats cooked in milk with a banana and some yoghurt. For lunch, rice with dal, vegetables and paneer, chicken or eggs, or pasta with lentils or chicken and a side of bread. Between meals, have fruit, a sandwich, a glass of milk or some toast with peanut butter. Dinner follows the same pattern as lunch.
Keep drinking through the day as well, especially if Sunday was hot or humid. If your stomach feels heavy after a long run, choose lower-fibre carbohydrate (white rice, plain toast, potatoes) for a meal or two and bring the fibre back once your gut settles.
When is constant hunger a warning sign?
If you're hungry every day, not just after long runs, the shortfall is probably across your whole week rather than one session. You'll often see it alongside other things: tiredness that easy weeks don't fix, poor sleep, stalled times, frequent colds, or irregular or missed periods.
Over months, a steady gap between what you eat and what you burn leads to low energy availability. That's the territory of Relative Energy Deficiency in Sport (REDs), which affects hormones, bone health, immunity and recovery (Mountjoy et al., British Journal of Sports Medicine, 2023). Energy availability is the number behind it. No supplement fixes it. Eating more, in a structured way, is the only thing that does.
See a doctor if constant hunger comes with weight loss you can't explain, unusual thirst, missed periods, or tiredness that doesn't lift with rest. Those can point to things beyond training. And if eating or training has started to feel stressful or out of your control, a clinician who works with athletes is the right person to talk to.
The Fueletics Perspective
I'd rather a runner be hungry on Monday than flat on Thursday. Day-after hunger tells you something useful: that day was under-fuelled. The fix is to stop letting appetite set the menu on long-run days. Plan the extra carbohydrate into Sunday's meals and keep Monday's portions higher, and the fridge-raiding mostly stops.
How much extra depends on your bodyweight, weekly distance and how hard the long run was, and those numbers change through a training block. That's what the Daily Fuelling Engine handles, by adjusting intake for training days and rest days automatically. If you want your own training-day and rest-day targets rather than a range from a table, start with a Fueletics assessment.
FAQ
Is it normal to be hungry two days after a long run?
Yes. Appetite catches up with energy spent slowly and only partly, so hunger can carry on for a day or two, especially after a run over 90 minutes or in a high-mileage week. If it lasts into the rest of the week, look at your overall intake.
Should I eat more on the rest day after a long run?
Yes. A rest day after a long run is still a refilling day for glycogen and muscle repair, so don't cut back to your lightest eating.
Why do I crave sugar after a long run?
Your carbohydrate stores are low, and sweet foods are the fastest carbohydrate your brain knows about. Eating enough carbohydrate at meals, including on the long-run day itself, usually takes the edge off the cravings.
Does being hungry after running mean I'm burning fat?
No. Hunger reflects an energy and glycogen shortfall, not fat loss as such. Ignoring it often leads to under-recovery and bigger hunger later.
Research References
Schubert MM, Sabapathy S, Leveritt M, Desbrow B. Acute exercise and hormones related to appetite regulation: a meta-analysis. Sports Med. 2014;44(3):387–403. doi:10.1007/s40279-013-0120-3
Schubert MM, Desbrow B, Sabapathy S, Leveritt M. Acute exercise and subsequent energy intake. A meta-analysis. Appetite. 2013;63:92–104. doi:10.1016/j.appet.2012.12.010
King JA, Garnham JO, Jackson AP, Kelly BM, Xenophontos S, Nimmo MA. Appetite-regulatory hormone responses on the day following a prolonged bout of moderate-intensity exercise. Physiol Behav. 2015;141:23–31. doi:10.1016/j.physbeh.2014.12.050
Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet. 2016;116(3):501–528. doi:10.1016/j.jand.2015.12.006
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med. 2023;57(17):1073–1097. doi:10.1136/bjsports-2023-106994
