Expert explains: what to eat before and after a run

How much should I eat to fuel a run?

Most people grew up with the attitude that you finish your plate, regardless of whether you already feel full or not. We should instead be thinking about eating intuitively. In terms of portion sizes, the easiest way is to look at your hand. Your protein is your palm, then a fist for carbohydrates and a thumb for fat. Obviously some things cross over, for example with avocado I wouldn't just have a thumb, but it helps as a general rule. You might think that it's a tiny amount, but it actually isn't. You can pile your plate high with veg – I don't limit my veg intake as it's a great source of nutrients. It's also another good source of carbohydrates in our diet, and runners especially do need carbohydrates. You're also filling up on fibre and other good stuff, rather than overloading the plate with less nutrient dense foods.

Learn about 20 high fibre recipes and try our high-fibre breakfast recipes.

Should you have protein before or after a workout?

Protein is a hot topic when it comes to running. Some people say you have to eat protein within 20 minutes of doing a run, but there's actually new evidence that suggests that we might not need to do that. The government recommends that you eat about 0.8 of protein per kilogram of your body weight per day, or up to about one gram per kilogram if you're very active. As long as you meet that target throughout the day, the studies suggest that we might not need to have it within this short window.

After a workout, you should be looking for more of a carbohydrate to protein ratio. You need to replenish your glycogen stores, your energy stores of carbohydrates, which is what fundamentally what your body uses as energy when you work out, whilst protein helps with the muscle repair. So, even something as basic as a skinny latte after a workout contains both carbohydrate and protein.

A lot of us can get obsessed with having a protein shake after a run or workout, but actually it could be something as simple as having a nutrient-rich lunch such as salmon, couscous and vegetables, which is a also great protein and carbohydrate source. Discover our top foods that give you energy.

What are complete proteins?

Our body needs complete proteins because they contain the nine essential amino acids and our body can't make these on its own. A lot of complete proteins are animal products, but there are also plant-based sources like quinoa. You can also mix and match your proteins. For example, that's why people so commonly eat rice and beans because by eating them together you get a complete protein and all nine amino acids. Discover our high protein meals, with veggie and vegan options.

Why do runners need carbohydrates?

Our body needs carbohydrates to function properly. Often when we think of carbs, we think of them as bad things because we're thinking about white pasta, cake and biscuits, but they're in beans and broccoli too.

Carbohydrates should make up almost 50 percent of our overall dietary intake. They are the body's preferred energy source, which is why it's so crucial for runners that we get enough carbs to fuel our bodies to run better and longer and faster and support whatever training you are doing.

The glycemic index is how fast your body can utilise the carbs. Most of the time I opt for slow release, low glycemic index carbs, such as oats and brown rice. Sweet potatoes are medium, but after you've worked out, that's when you can go for something that's high GI to replenish your energy. If you want to have that chocolate biscuit or something with a high GI, have it after something with a lower GI, for example as dessert after your lunch.

Are energy gels worth it?

If you run a lot, the cost of buying energy gels can add up. Making your own can be easy at it uses such simple ingredients, such as fruit, maple syrup and chia seeds, and you can leave it bubbling away. It's about combining sugar sources so that the sugars and the carbohydrates can be released at different times and therefore keeps you energised for longer. Pre-made energy gels make it easy as this ratio should already be spot on. You want to make sure that you take it at the right time to optimise your performance, such as every half hour or 45 minutes. That said, if you're doing a 10k or exercising for less than an hour, you probably won't need a gel. Depending on your gels, you may need to add water to them. Before the race do your research to find out where the water stations are and you may want to amend your intake of gels based on that.

Try our recipes with chia seeds.

How should you fuel before a run?

If you're doing a 5k, for example, you don't necessarily need to eat something beforehand, although it depends on what works for you. If you don't want to eat anything, you could have a milky coffee which is both a protein and carbohydrate source. Although we have been led to believe breakfast is the most important meal of the day, not everyone is built the same. So if you don't feel like you need breakfast or you can just have a milky coffee and you're good to go, then stick with it.

If you're doing a longer run, you'll want to fuel your body so that it can perform at its best. The optimum time is about two to three hours beforehand. The general rule of thumb for fuelling during a run is you should eat 30 to 90 grams of carbohydrate per hour for the first one to three hours, and then after that 30 to 90 grams of carbohydrate per hour. The most important thing is to practice with this during your training otherwise it's a lot of carbohydrates to put into your stomach with not much else mixed in.

Should you carb load before a run or workout?

Carb loading is literally stepping up your carb intake. I usually add about a hundred calories extra per day, in the four or five days leading up to a marathon. By doing it gradually, you don't end up feeling sluggish. For example, if you don't want to add more food bulk, incorporating a sports drink is one way, or you could add an extra portion at one of your less carb-heavy meals, or an extra snack.

You don't want to get to race day and feel weighed down – carbohydrates make your body retain water, which can make you feel like you're putting on weight. The night before a marathon, I try and stick to something that I've had before as you don't want to incorporate too much salt, for example, or something that might irritate your stomach. I'll typically have chicken sausage, pasta and tomato sauce.

What's the best way to refuel after training?

In general I would say if you've just finished your marathon and that's your goal race, eat what you want. If you've just finished a training run and you are going to run the next day, or you've got another workout a day or two later, then you want to give your body the best fuel to recover and get ready to go again.

I use a 3:1 carbohydrate to protein ratio, whether that's a quick recovery shake or roast chicken with potatoes and root vegetables. Again, it comes back to the portion sizes – you need more carbohydrate than you would have on a normal meal. So for example, if you're eating stew with rice, you would have one part stew and three parts rice.

Although, it's what your body can manage because you don't want to be force feeding yourself and feel unwell. You want to eat enough so that you'll wake up the next day and feel great. If that means having something smaller, such as a snack or even drink with a good ratio, then having a good meal later on, it's about working out what works best for you.