Posted on August 15, 2014 by Jenny Cromack

How many people do you know who have run a marathon and put weight on whilst they are training or have relied on marathon training to help them lose weight but to no avail. Now, if you’re a regular reader of our blogs you will know that steady state running is not the best thing for weight loss anyway, but I’d also probably argue that these people don’t understand carb loading and have probably been feasting on too many carbs! Also, think about your friend who runs 10k’s and tells you the night before the race they can eat a huge pile of pasta because they are ‘carb loading’.

So what is carb loading? Do you need to do it? Is it beneficial….not just for running but other sporting activities too? I’m hoping this blog will shed some light on carb loading and when it is needed. As I am a runner, I’ll probably reference it to running quite a bit, but in general you should be able to apply this to other sports activities.

So let’s start with a surprising stat which often shocks many of my personal training clients when I tell them! At any time your body can hold enough energy (circa 1800 calories)  to sustain around 90 minutes of exercise. So for those of you who turn up for a session panicking that you haven’t eaten in the last hour, don’t worry you do have enough energy to get through your session! Now, I’m not saying you don’t have to skip your pre-workout snack but if you do then don’t sweat about it. (For a great blog about what to eat before a workout click here!)

But based on this stat I think it’s safe to say that if you are training for anything for less than 60-90 minutes then you don’t have to carb load. Therefore, personally, I don’t think it is necessary to carb load for a 10k race, but only for races 10 miles or above.

So what happens after these 90 minutes? Well if you don’t refuel on your long training sessions or races then you will more than likely hit the wall as your body continues to run out of energy (and from experience it’s not fun!). So what should you do to avoid this? Firstly you can take extra fuel on board during your training or race (which I will blog about next week) and secondly you can carb load on the days leading up to your long run or race day.

What Is Carb Loading?

Carb loading was originally developed in the 1960’s to boost athlete’s energy stores befpre endurance events. The school of thought in the 60’s about carb loading is different to today’s mindset. The original carb load model was to encourage athletes to reduce their carbohydrate stores for three days at the start of the week before a big event, they would follow a low carb diet and couple this with a high volume of exercise. Then in the few days before the event the athletes would reduce their exercise volume and follow a high carb diet, the theory being that the body would be able to store a high amount of energy.

However, this method didn’t seem to work as the training intensity was too high before a race, the low carb phase left athletes low in energy and morale and then they found it physically hard to take enough carbs on board in the days leading up to the big event often resulting in a poor performance.

Therefore the theory these days has changed and it is now encouraged to gradually increase carbohydrate stores in the 3 days leading up to the event.

Guidelines For Carb Loading

• Aim for a carb intake of around 8-10g per kg of your body weight per day on the 3 days before a long training run or race day.

• Just because you are eating more carbs doesn’t mean you have to increase calories…eat the same amount, just more from carbohydrates.

• Don’t gorge on big meals, eat little and often during the day.

• Increase your intake of natural carbohydrates – brown rice, quinoa, bulgar wheat.

• You should still eat protein, not only is it essential for muscle recovery and repair but it also slows the digestion of carbs and therefore encourages energy to be released slowly….perfect for endurance races.

• For gram of carb you store you also store 3g of water so don’t panic if you gain weight in the days leading up to an event, you should lose this after the race!

• Experiment before the big day….you don’t want to try and new tactics or foods on the big day and risk an upset stomach

Personally, I think these guidelines only apply for anything above 90 minutes of exercise, anything less than this and you should follow your normal nutritional plan

It’s worth noting that, as with everything in life, each person is different. For example as I am shorter and lighter than the average person I don’t tend to burn as many calories per mile as my taller and heavier counterparts so I only burn 85 calories per mile as opposed to the average of 100 calories per mile. Therefore this means that whilst most people, in theory, have enough stored energy to run 18 miles before taking extra energy on board, I, in theory, should be able to run 21 miles without taking any extra fuel on board, although I’d suggest taking fuel on board earlier than this so you don’t hit the wall.