26 June 2015

Nutrition Know How For Half Marathons

The key to a PB in the half marathon distance isn’t just about clocking up the mileage in training, it’s also about making savvy food choices. And when it comes to long distance running, there are two nutrients and one mineral to get wise to.


1. Carbohydrate

While there’s not one sole source of energy when it comes to running, carbohydrate plays the leading lady in supplying energy, particularly as you increase speed. Carbohydrate is stored in the muscles and liver as glycogen. If your reserves run low, running will be tough – your legs will start to feel like they’re wading through mud. You can get around a half without hitting the much-fabled wall that hits marathon runners, but for optimum performance, what you eat will hold the key to unlocking that half marathon PB.

Before long runs

Balance is key when it comes to considering carbs – if you over-do your intake in the months and weeks leading up to a half marathon you may gain weight, which will have the reverse effect of helping you perform at your best come race day. For the half marathon distance, you only really need to think about carbs for runs of over 2 hours in training and in the 24 hours before the race.

All the talk of carb-loading and pasta parties the evening before long races is to get carbohydrate stores stocked up. Carb loading doesn’t necessarily mean vast bowls of pasta and porridge – besides tasting bland, ODing on these foods if you’re not used to them can leave you feeling sluggish and bloated. A meal high in low GI carbohydrates, moderate in protein and low in fat will give your body all the nutrients it needs to power through a race.

Boosting the carbohydrate content of meals can by done relatively easily by simply adding a bigger portion of your preferred carbohydrate food choices at meal times. Adding fruit juice to your meal will also help to top up your supply, and remember that carbs are also found in veg too – it’s a small amount in comparison to pasta, but root vegetables, bananas and dried fruit contain higher amounts - and every little helps.

Get your carb quota:

Wholegrain pasta – 73g (dried) per 100g

Jacket potato – 32g per 100g

Rice – 31g per 100g

Bagels – 50g per 100g

Quinoa – 64g per 100g

Oatcake biscuit – 53g per 100g

Small bread roll – 50g per 100g

Cornflakes – 84g per 100g

Muesli – 63g per 100g

Rice cakes – 81g per 100g

Fruit juice – 11g per 100ml

During long runs

Do you really need to fuel during a half marathon? Unless you’re a very fast runner used to running without fuel in a race it’s wise to think about carbohydrate during a race.

The body can roughly store around 2,000 kcals of glycogen at any one time, and after around 90 minutes of running your muscles will begin to run low on its energy stores (this is a guideline figure – the actual amount varies according to how fast you run and your own body composition for glycogen storage).

High GI sugary foods are best during a run as they release energy quickly, delivering glucose for your body to use rapidly. Energy gels and drinks are designed with this in mind, or if you prefer the natural method, try bananas, oranges, honey or dried fruit. Sports nutritionists recommend fuelling every 45-60 minutes during a long run, with around 30-60 grams of carbohydrate (120-140 calories) per hour. Usually races will have two or three fuelling stations with water and sports drinks.

The golden rule for race fuel is to always practise ahead of a race. Pure sugar can have nasty effects on your gut, but you can train your stomach to get used to gels and sports drinks.

2. Protein

You’ve probably seen gym bunnies clutching a protein shake, and in half marathon training they can serve a purpose too. After a long run, as well as replenishing carbs, protein is the key nutrient as it helps to rebuild and repair muscle and speed up your recovery. If you opt for a commercial sports product, recovery bars are specially designed to give you the right nutrient mix you need after a run, with a blend of roughly 30% protein to 70% carbohydrate.

You can of course refuel naturally too, and chocolate milk is the simple, age-old recovery food for runners since it contains the optimum mix of protein and carbs.

Sports nutritionists recommend eating as soon as possible after training to help make adaptations. The body is primed to replenish its carb stores and soak up muscle-repairing protein immediately after a run so don’t leave it longer than an hour to refuel.

Foods packing a protein punch:

 - Milk

 - Cheese

 - Yoghurt

 - White meats

 - Eggs

3. Salts

If you’ve ever tasted your skin after a long run you’ll understand that sweat contains salt.  Sweating – your body's cooling system – removes excess heat through evaporation, and besides water, you’ll also lose salts, which is why you sometimes see runners with telltale tide marks on their foreheads and legs after a run.

Electrolytes (salts) are important for muscle function. They process electrical impulses from the nerves, helping to send messages to the muscles to contract, so it's important to replenish electrolytes as well as water on long runs. Staying properly hydrated with electrolytes can also help to beat cramp.

Electrolytes will be in most energy drinks, or you can buy electrolyte tablets to drop into water. Keep in mind weather conditions when thinking about hydration – on hot days the more you’ll sweat, and the more you’ll need to replenish lost fluids. Most sports nutritionists advise to drink to thirst and drink little and often unless the conditions are extreme when you’ll need more of a strategy. 

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