Carbs are the body’s primary source of fuel, so they should form a significant part of your diet – around 60 per cent is a good general rule. Stored as glycogen in your muscles and liver, carbohydrate is the fuel your body burns when you run for prolonged periods. It will carry you through long training efforts, but your body can only store roughly 1,600 calories, which is why you need to refuel on the go if you’re running for more than a couple of hours.
Simple v complex
Carbs are classed as simple or complex, depending on their chemical structure. In basic terms, simple carbs are made up of one or more sugars – such as glucose, fructose and lactose – while complex carbs also include starches and fibre. When it comes to carbs and running, the most useful measure is the Glycaemic Index (GI). This is a number given to carbohydrate-rich food based on how quickly it raises your blood sugar levels after you eat it. A food with a high GI, such as a sugary drink, will result in a rapid rise in blood sugar. A food with a low GI, such as porridge, will produce a slower rise, resulting in a steadier supply of energy.
A huge plate of pasta the night before a race is a runner’s rite of passage, but there is some debate among sports nutritionists on the best way to carbo load. To ensure you start a race with as much stored glycogen as possible, aim to consume a diet high in carbs, protein, vitamins and minerals, combined with plenty of fluids for two to three days before the race.
Why is protein important?
Too little protein may lead to injuries, fatigue and mood swings. It’s easy to squeeze protein out of your diet if you’re skimping on calories while making a point of eating lots of carbohydrates to fuel your runs.
A breakfast of fruit and toast, for instance, is high in carbohydrate and low in fat, but doesn’t contain the quality protein you need to repair and renew muscles that are damaged during hard or long training sessions. Your body also turns to protein for fuel when it’s run out of glycogen toward the end of a long run.
Road to recovery
Sports nutritionists agree that the best way to recover is by consuming a combination of carbs and protein in a post-workout snack within 30 minutes of finishing your training. Aim for a ratio of 3:1 carbs to protein: yoghurt with granola and dried fruit; a bagel with peanut butter and 250ml fruit juice; a tuna, turkey or egg sandwich; or a bowl of cereal with milk and sliced banana. And if you’re attempting to build muscle by including resistance exercises in your training schedule, your protein intake should be higher still. Aim to eat 1.6g of protein per kilo of body weight.
A balanced diet should provide all the protein you need, but if you think you’re struggling to consume the required amount, a simple way to supplement your intake is with a post-workout protein shake.
Your body uses fat for fuel. We all have enough stored fat to cover more than 1,000 miles – as long as we don’t break into a jog. As soon as you start to run, your body switches to carbs for fuel. When it comes to the fats you consume in your daily diet, the type you eat – rather than the amount – is key. All fats were not created equal: there are good and bad fats, and some that fall somewhere in-between.
Monounsaturated fats raise your ‘good’ HDL cholesterol, which promotes clean arteries and protects against heart disease. Good sources of monounsaturated fats include oily fish (such as mackerel and salmon), avocados, olives, nuts and peanut butter. Polyunsaturated fats are also good for you. They tend to be liquid at room temperature – sunflower and canola (rapeseed) oil are good choices. A combination of these good fats should make up around 25 per cent of your diet.
and the bad…
Saturated fats raise levels of ‘bad’ LDL cholesterol and have been linked to a higher risk of heart disease and stroke. They are mostly animal fats and tend to have a buttery consistency at room temperature. Red meat, poultry, butter and full-fat milk all fall into this category. Trans-fats are created when hydrogen is added to vegetable oil, to make it more solid and less likely to turn rancid. The process is used to give products a longer shelf life, but it may shorten yours: trans-fats raise your levels of bad cholesterol, fur up your arteries and have even been linked to a greater risk of developing Alzheimer’s disease. Check a product’s ingredients and put it back down if you see the words ‘hydrogenated vegetable oil.’
Quality and quantity
As you ramp up your mileage, it’s crucial you consume enough quality carbohydrates and protein. When you’re running for more than 60 minutes, aim to consume 100g to 200g of fuel every 30 to 60 minutes to keep your energy stores topped up. After a long run, eat a 300-to-400-calorie snack with a 3:1 mix of carbs and protein within 30 minutes to jump-start muscle recovery. Long runs are also a good time to practise the balance of food and fluids that will ensure you’ll be ready for race day.
The two minerals that women runners need to pay the most attention to are calcium and iron. “You will need to up your iron levels, as menstruating women – and, in fact, athletes in general – can be prone to iron deficiency,” says nutritionist Shona Wilkinson (nutricentre.com). Your recommended daily allowance (RDA) for iron is 18 to 20mg; good sources of the mineral include liver, iron-fortified cereal, dried fruit, beef and spinach.
Your RDA for calcium is 1,000 to 1,300mg; good sources are dairy products, dark-green leafy vegetables, broccoli, tinned sardines and salmon. Stress fractures – which are common among female runners – can be prevented by adding more calcium and vitamin D to your diet, according to the Orthopaedic Research Society. Researchers gave one group of women 2,000mg of calcium and 800IU of vitamin D daily, while another group received half that amount. The women who took the higher dosage experienced 27 per cent fewer fractures. To ensure you get the right amount of other key nutrients, check out RDA on a Plate, opposite.
A pinch of salt
Runners also need to be aware of their salt intake. Too much salt is linked to high blood pressure – which can cause heart attacks and strokes. Government estimates suggest that cutting salt intake by a third, from the average of 9.5g, would lead to a 10 per cent drop in heart disease, saving 35,000 lives a year. Excess salt also leeches calcium from bones, weakening them.
But even runners who avoid salt bombs such as processed foods get all the salt they need without trying.
The Food Standard Agency’s (FSA) recommended daily salt allowance is six grams, and if you have toast and cereal for breakfast, a pasta salad and yoghurt for lunch, and a midday handful of low-fat crisps, your salt intake would be 5.5g – before dinner.
On the other hand, if it’s hot or if you’re training hard, you can sweat out a lot of salt – as much as 3g in an hour. Losing that much sodium may be bad news, since it is essential for hydration. “Sodium helps regulate the body’s fluid levels,” says Bob Seebohar, author of Nutrition Periodization for Endurance Athletes. The loss of salt is also connected to other running problems, such as cramping. So exactly how much salt should runners ingest?
The answer depends on several factors, including the weather and your physiology. A heavy sweater
who has a high salt concentration could lose about 3g of salt during a 5K, whereas a light sweater might only lose 0.4g of salt, according to a study at the Gatorade Sports Science Institute in Illinois, in the US. Elite athletes take a salt test to know how much sodium to replace. All that the rest of us need to do is look at our skin. If you can play noughts and crosses in the white residue, consuming a salty snack or a sports drink with about 0.2g of salt per serving after a workout will help your body to rehydrate better. Turn to page 140 for more on how to hydrate before, during and after a run.
Watching your sugar intake will help you to avoid rapid swings in mood and energy levels when you’re menstruating. Opt for wholegrain versions of pasta and bread, and eat plenty of fresh veg. You should also cut out the coffee: caffeine has been shown to increase some symptoms of premenstrual syndrome (PMS), such as irritability, mood swings and breast tenderness. The good news is that women who exercise report milder PMS than sedentary women.
How much do I need?
To work out how many carbs to include in your daily diet, multiply your weight in kilograms by seven. So, if you weigh 70kg (the weight of the average British woman), you need 490g of carbohydrate.
To calculate how much protein, you need every day multiply your weight in kilograms by 1.3. So, if you weigh 70kg, you’ll need to consume 91g of protein every day.
According to current NHS guidelines, the average British woman should include no more than 20g of saturated fat in her daily diet. Focus instead on upping your intake of unsaturated fat.
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