Carb Loading Before a Race: A South African Runner's Guide

Carb loading is the trick that gets every first-time Comrades or Two Oceans runner nervous, and for good reason: get it right and you float through the back half, get it wrong and you're bloated at the start or bonking at 30km. The good news is it's simpler than the internet makes it sound, and you can do it beautifully on everyday South African food. Here's exactly how to carb load before a race, how many carbs you actually need, what to eat (pap and potatoes count), and the mistakes that trip up most runners.

What Is Carb Loading and Does It Work?

Carb loading is a fuelling strategy where you eat extra carbohydrate in the days before a long race to pack your muscles and liver with glycogen, your body's premium fuel. It genuinely works for events lasting longer than about 90 minutes, which covers every distance from a tough half marathon up to Comrades. For anything under an hour, it makes little difference, your body already holds enough fuel.

Worth being honest, though: the old image of a runner inhaling three plates of pasta the night before is mostly a myth. The science, going back to Hawley's classic 1997 review, shows it's about steadily raising your glycogen stores over a couple of days, not one giant blowout meal. Done properly it can delay the wall and protect your finish. Done as a single pasta binge, it just leaves you heavy.

How Many Carbs Do You Need to Carb Load?

Aim for roughly 8 to 12g of carbohydrate per kilogram of body weight per day in the loading window, which for a 70kg runner works out to around 560 to 840g of carbs daily. That's a lot more than it sounds, and most runners undershoot it. A simpler floor to remember: most runners benefit from at least 500g of carbs a day in the final stretch, with smaller runners needing less.

The National Strength and Conditioning Association describes carb loading as saturating your muscle glycogen stores before longer events, and the practical way to hit those numbers is to make carbs the star of every meal and snack rather than trying to eat enormous portions in one sitting. Spread it across the day. Your stomach will thank you.

When Should You Start Carb Loading?

Start carb loading 2 to 3 days before your race, not the night before, while you taper your training right down at the same time. The taper is half the magic: as you cut your running volume, your muscles stop burning through glycogen and start storing the extra carbs instead. This is what lets them supercompensate and hold more fuel than usual.

For a Saturday Two Oceans or a Comrades on a Sunday, that means starting your load on the Wednesday or Thursday. Practise it before your goal race too. Trial a two-day load before your longest training run so you know how your stomach handles it. Race week is the worst time to discover a food disagrees with you.

What South African Foods Are Best for Carb Loading?

The best carb-loading foods are simple, starchy and easy to digest: white rice, pasta, potatoes, samp, pap, white bread, bananas and sports drinks all do the job brilliantly. You don't need fancy imported gels or special powders to load, your kitchen already has everything. A plate of pap with a low-fat sauce, a potato-heavy supper, or a big bowl of rice are all proper carb-loading meals.

One key tip for the final 24 to 48 hours: go lower in fibre. Swap brown rice and wholewheat for white versions, ease off the salads and beans, and stick to refined, easy-to-digest carbs. High fibre right before a race is a classic cause of an unhappy stomach on the start line. Save the health-food virtue for after the medal.

What Are the Most Common Carb-Loading Mistakes?

The most common carb-loading mistake is adding fat and protein instead of replacing them, so you end up eating a huge creamy pasta or a greasy pizza and feel awful. Carb loading means swapping some of your usual fat and protein for carbs, not piling extra food on top. Keep the meals lower in fat and you'll feel light, not stuffed.

Two more traps catch runners every year. First, don't panic about the scale: every gram of glycogen you store holds about 3g of water, so a 1 to 2kg gain is normal and is actually your body banking hydration for race day. Second, don't leave it all to the last supper. A single big meal can't undo two days of under-fuelling. Spread the load.

Carb Loading vs Race-Day Fuelling: You Need Both

Carb loading fills your tank before the race, but on anything beyond about 90 minutes you still need to top up with carbs during the run, because your stored glycogen runs low no matter how well you loaded. The two work together. A good load buys you a strong first half; in-race fuelling carries you through the second.

This is where your race-day kit earns its place. On the road we reach for gels like the 32Gi Sports Gel, a low-GI option whose credit-card sachet folds open one-handed, or a SIS Beta Fuel Gel for a bigger 40g carb hit late in a long race. For the full race-day plan, our Comrades Marathon nutrition plan maps out exactly when to take what. Carb loading and smart fuelling together are what get you to the finish strong.

We hand-select every race-day product we stock because we've tested them through our own Comrades and Two Oceans builds. Browse our competition day range and get your fuelling sorted well before race week.