A Sports Dietitian’s guide to Carbohydrate Loading
Erin Percy, Accredited Sports Dietitian
Carbohydrate loading is one of the simplest ways athletes can boost their energy stores before a big event. Carb loading helps you start your race, game, or tournament with your muscles fully fueled, giving you the best chance of performing strongly from start to finish. In this guide, we’ll break down when carb loading is actually useful, how to do it properly, and the small tweaks that can make a big difference to your comfort and performance on event day.
When to Carb Load
Carb loading is most useful for athletes who need long‑lasting energy for performance in an upcoming event. The goal is to maximise muscle glycogen stores, your body’s main fuel source during endurance exercise. Higher glycogen means delaying fatigue and a stronger, more consistent performance.
Carb loading is recommended for:
Endurance and ultra‑endurance events
e.g., triathlon, cycling, distance running.
Events lasting longer than 90 minutes
This includes team sports with long game times or high‑intensity play (e.g., AFL, soccer, hockey).
Athletes at risk of late‑game fatigue
Especially those with high running loads, repeated sprints, or heavy workloads.
If your event is shorter than 90 minutes, a carb load is usually not necessary. Your everyday nutrition and pre‑event meal will typically provide enough fuel.
You might also consider carb loading before tournament weekends, finals, qualifiers or any situation where you struggle to keep up with your energy demands. It can also be helpful if nerves impact your appetite on game or race day. Topping up your fuel stores ahead of time ensures you’re still well‑prepared even if you can’t eat much on the morning of your event.
How to Carb Load
Once you’ve identified that carb loading is right for your event, the next step is understanding how to do it properly.
The aim is simple: significantly increase your carbohydrate intake so your muscles can store as much glycogen as possible. This is paired with a lower training load, which helps your body actually retain those glycogen stores rather than burning through them.
Carb loading isn’t about eating as much food as possible, it’s about eating more of the right foods, in the right quantities, at the right time.
Two common carb‑loading methods
1. 24–48 hours before the event
Aim for 10–12 g carbohydrate per kg body weight per day
Best for athletes who prefer a shorter, more intense loading phase.
2. Traditional 3‑day load
Aim for 8–10 g carbohydrate per kg body weight per day
Allows more time to spread out the extra food.
Both approaches work well, and the best choice really depends on your event demands, your training schedule, and your personal preferences. Some athletes feel great with a short, sharp load, while others prefer the steadiness of a three‑day approach.
To help give you an idea of what this looks like in practice, here’s an example day of eating that for a 70kg athlete needing to meet 700g of carbs per day
Breakfast: 1 cup Clusters type muesli + Banana + ½ cup sweet yoghurt + milk + drizzle of honey (135g)
Snack 1: 1 x White english muffins + 2 Tbsp Jam + 200ml Sweetened Pineapple juice (85g)
Lunch: 2 cups Pasta with sauce and chicken + canned plums / banana/ mango and sweet yoghurt + 1 375ml can of Sprite (146g)
Snack 2: 600ml powerade + 1 Hawaiian pizza roll + 40g snack packet of Apricot delights (110g)
Dinner: Honey Soy chicken stir fry + 1.5 cups Rice + 200ml glass of juice (115g)
Snack 3: 1 Weis and ice cream bar + 5 tsp Milo with 1 cup skim milk + 6 Allens Snakes (110g)
It’s very easy to under-calculate your carbohydrate needs if you’re not following a structured plan. Without support, it’s common to fall short of the carb levels required to properly maximise glycogen stores.
Working with a sports dietitian can take out all the guesswork. They can help you calculate your exact targets and build a plan that fits your appetite, routine, and event demands, ensuring you’re truly fuelled for peak performance.
Low residue (Low-fibre) - Keeping it Digestible
You will notice in that example, they aren’t the “healthiest” foods and are not what we recommend in a day to day diet. Not exactly much calcium, iron or fibre in Powerade or snake lollies! However switching to a low‑residue diet in the final 24–48 hours can help reduce gut discomfort on race day.
Why low‑residue helps
Reduces the risk of bloating, cramping, or urgent bathroom stops during the event.
Helps prevent early fullness, making it easier to meet high carb targets.
Minimises fibre in the gut, which can reduce gastrointestinal symptoms during exercise.
Low‑residue food choices
Choose more of:
“White” versions of grains: white bread, white pasta, white rice, low‑fibre cereals
Refined grain products: crumpets, pancakes, English muffins
Pulp‑free juices, smoothies made with low‑fibre fruits
Mashed or pureed fruits/vegetables (e.g., applesauce, mashed pumpkin, potato)
Dairy foods (yoghurt, milk, custard) and Lean meats, eggs, tofu are all considered low residue too but they don’t add carbs to your loading protocol.
Choose less of:
Raw vegetables, salads, skins, seeds
High‑fibre fruits (berries, apples with skin, pears)
Nuts, seeds, legumes
Wholegrain breads, brown rice, high‑fibre cereals
If it’s your first time trying a carb load, working with one of our sports dietitians is the best way to make sure you’re getting the right advice and hitting the carbohydrate targets you need. Having personalised guidance sets you up for success and gives you confidence heading into your event.
Book an appointment with Erin, your Sports Dietitian today.