On the run up to a long distance race (typically 10 miles or longer), I often hear people talk about “carb loading” the night before. A lot of runners know that eating high carb foods, such as pasta or pizza, before a longer race is good idea but very few seem to know how to carb load correctly or even why you need to do it. Don’t get me wrong, I am definitely one of those people who doesn’t need an excuse to eat a large plate full of lovely Italian food so the idea of having a ready made excuse for stuffing my face with pasta sounds good to me. Unfortunately, as with most things worth doing, it’s not that simple so I thought I would take the opportunity to share with you my thoughts on carb loading – the correct way.

What is “carb loading”?

First of all, why do we need to “carb load”? When we eat carbs (or carbohydrates to give them their longer name) our bodies store glycogen in our muscles and liver. It is this glycogen that our bodies then use when we need energy whilst performing exercise such as running (glycogen is the body's most readily accessible form of energy). Glycogen is not our only source of energy though and the amount we can store is limited. When our body runs out of glycogen as a fuel source it has to use our fat stores – but this is much harder work for the body as the conversion of fat to fuel is not as efficient. The result is that when your body runs out of glycogen during a race you reach the point known as “hitting the wall” (not a pleasant feeling as anyone who has experienced it will tell you) and you will start to slow down as your body changes to using your fat stores as fuel.

Carb loading is therefore the process of filling up your muscles with as much glycogen as possible, which can then be released for fuel during your run. The bad news is that you cannot completely saturate your muscles with glycogen from a single meal (sorry), but the good news is that you do get to eat more carbs over a longer period on the build up to a race (yay)!

What should I eat?

Stick with easy to digest carbs that are not too high in fibre as a high fibre diet can cause stomach upset – and that is certainly something that you do not want to experience mid-race!  Also try to avoid combining your carbs with high fat foods (e.g. butter, cream, oils, cheese) or too much protein as both of these can fill you up faster than carbs and take longer to digest.  Stick with a tomato sauce for your pasta rather than a rich creamy one. Use jam on your toast instead of butter.

Something that tends to go against the current trend is to allow yourself to eat white bread (lower in fibre than wholemeal) or baked white potato (with the skin removed to reduce the fibre content).  Fruit is high in carbs but can also be high in fibre so choose wisely – often the fibre in fruit is mostly in the skin so try peeling your apples, pears, peaches, etc…, or go with bananas which are naturally low in fibre.

How much should I eat?

Typical recommendations are to eat approximately 8-9 grams of carb per 1 Kg of body weight (so an 80 Kg runner would be eating about 640 – 720 grams of carbs per day – this equates to about 2,500 – 2,880 calories of carbs per day).

What do I need to do – the 5 steps?

Combining a good “carb loading” schedule with a taper in your running training (where you are using less of your stored glycogen) will ensure you're giving yourself the best chance of reaching the start line with your glycogen stores fully stocked.

Step 1: 4-6 weeks before – Practice

Ideally you should start practising “carb loading” about 4-6 weeks before your target race so that you can determine which foods work best for you but also to ensure you don’t start eating ones that could disagree with you – not good going into a big race! Practice by eating more carbs 2 or 3 days before your long runs.

Step 2: 1 week before – Plan

About a week before the race I would recommend making a plan so that you can be fully prepared – it’s much easier to eat the correct foods when you have a plan. This is especially important if you have to travel for the race. Think ahead about snacks and any restaurants that you might be using in the final few days before the race.

Step 3: 2-3 days before – Switch

Now it’s time to put your practice into practice and follow your plan.  During this time you diet should consist of about 85-95% carbs.  Also, ideally eat after your taper runs as this is when your muscles are best prepared to store glycogen.

Step 4: The night before – Control

Don’t go mad!  Stick with something reasonably small but make sure it’s high carb.  Aim to eat early enough that you give your body plenty of time to digest the food and so that you don’t wake up on race day feeling stuffed!

Step 5: The morning – Breakfast

So you’ve gone to all the trouble of maximising your carb stores over the previous few days, don’t ruin that by leaving your stores deplete overnight and not topping them up again.  Aim to eat a reasonably high carb meal/snack (approx. 150 grams) about 3 hours before the race.  If it’s an early race, get up – eat – go back to bed.  If you are not used to having breakfast before a run make sure you take the time to practice in the 4-6 weeks period before race day.

Anything else?

Don’t worry if you step on the scales whilst carb loading and find that you have put on a few pounds (maybe even as much as 4-6 extra pounds) -this just means you have probably carb loaded properly.  When your body stores extra carbs it also stores extra water (approx. 3 grams of water for every 1 gram of carb) – the net benefit of this is that you will not only be fully fuelled but you will be better hydrated as well!

Carb loading won’t make you any faster in your race but it will allow you to run better for longer (and maybe even avoid hitting the wall).

Don’t waste all the hard work and effort that you have put into training for your distance race by not fuelling your body correctly. Follow my advice above and head to that start line fully fuelled and raring to go!

If you’ve enjoyed my post please feel free to leave a comment below – or even better share it so that others can enjoy it too – thanks for reading.

Best wishes

Barrie