Carb Loading 101

With the London Marathon just 4 days away, the running side of training is done (I actually have just one easy 10 minute left!) all efforts now need to be concentrated on fueling. As I have been tapering for around a week already, my muscles are already starting to refill with Glycogen following the months of constant depletion from long, intense training. Physically I can feel this, especially over the last few days when during my last runs I have felt heavy! I have to keep reminding myself this is a good thing as fuel is what's going to get me round the course.

Carb loading is a term used frequently in running and endurance circles but what does it actually mean? Put simply, it the process of increasing the amount of calories you consume from Carbohydrates in order to maximize the amount of Glycogen in your muscles. This is essential in endurance events as Glycogen will be your main fuel source and is most efficiently converted into energy. Once depleted, you will be forced to burn fat and finally muscle which won't provide the same amount of energy and is slower to metabolise meaning you will find activity much more challenging despite levels of fitness.

Historically, it was advised to completely deplete Glycogen stores by consuming a low carb diet for around 4 days, then switching to high carbs to refill. Thankfully, more modern research has demonstrated there is no need to empty first (which is a great thing for all us Carb lovers!)

So how much Carbohydrate actually constitutes loading - well, it varies from person to person but typically you should aim for 4 grams of Carbs for each KG of body weight. So, if you weigh 60 kg  then you would need 240g. Each gram of carbohydrate is 4 calories (on average) so this is a total of 960 calories. You can start loading from 5 days out - I personally plan to start tomorrow as my diet is already pretty carb heavy. Try to distribute your intake evenly throughout the day and by meal to get the most from your diet.

You can get some level of Carbs from pretty much every food group out there (meat and fish being the exception for the most part) however the volume and quality varies dramatically. Below I have rounded up the highest carb containing foods by group, along with their volumes for reference. By focusing on these foods, you can ensure you're able to hit the needed intake amounts as focusing on lesser carb heavy foods, you will become full before hitting the requirement.

Fruit	Measure	Carb content in Grams
Blueberries	1/2 cup	25
Banana	1 Whole	27
Mango	1 Whole	31
Papaya	1 Whole	33
Pear	1 Whole	26
Vegetables	Measure	Carb content in Grams
Sweetcorn	1 cup	44
Potato	1 Whole	43
Sweet Potato	1 Whole	28
Grains	Measure	Carb content in Grams
Bagel	1 Whole	35 - 50
Bread	2 Slice's	25
Bulgar	1 Cup	34
Cous Cous	1 cup	36
Croissant	1 Whole	26
English Muffin	1 Whole	25
Muffin	1 Whole	29 - 28
Noodles	1 Cup	40
Pita	1 Whole	33
Rice	1 cup	44
Spaghetti	1 cup	40
Beans	Measure	Carb content in Grams
Baked Beans	1/2 Cup	24
Misc	Measure	Carb content in Grams
Frozen Yogurt	1 Cup	36
Cake	1 piece	34 - 50
Brownie	1 piece	36

Note that I whilst have included some desserts, the Carbs here come pretty much entirely from sugar which will be expended much quicker than those in whole foods. However, given what we're about to undertake, a little indulgence is as good for the body as it is for the mind!

Good luck to everyone running London or any other race this weekend - remember, all the hard work has already been done so relax, smile and enjoy!