Eating for activity – a runner’s guide

Adam Keenan
Health Adviser and sports enthusiast
11 September 2019
Next review due September 2022

Knowing what to eat to fuel your training and how to prep for that big race can be tricky. In this article, I share my own experience of fuelling throughout my training and on race day.

Rugby league, boxing, cycling, running – you name it, I love it! I’m a keen sportsman and take part in lots of different sporting events, which requires me to train and eat differently depending on what I’ve got coming up. At the moment I’m training for a half marathon.

A half marathon is an endurance event, meaning it’ll test my ability to keep going until I reach the finish line. What it has in common with the other sports that I take part in is that it requires a certain level of aerobic fitness. But (as I’m realising) it calls for a slightly different nutritional strategy too. So, here’s everything you need to know about my half-marathon food prep.

Maintaining weight

Running burns lots of calories. But losing weight isn’t a goal for me, so I try to eat enough food and consume enough calories to maintain my weight at a healthy level. This is particularly important as I like to keep up my resistance (or weight) training alongside my half-marathon training too.

How many calories you need to eat varies from one person to another and depends on things like your age, gender and activity levels. As a rough guide, women need around 2,000 calories each day and men need 2,500. But as you start running and training more, you’ll burn more calories and will ultimately need to consume more. The best tip I can give for anyone increasing their activity levels is to be guided by your body; if you’re hungry or lacking energy – eat!

But don’t just fill up on any old rubbish, remember to eat a healthy, balanced diet, which consists of good sources of carbohydrates, protein and fats. A healthy diet should provide all the components and nutrients your body needs to perform and recover well.

Carbohydrates and energy levels

Carbohydrates are the main source of fuel for exercising muscles. They’re broken down into a type of sugar known as glucose, which provides immediate energy to your body. They’re also stored in your muscles as something called glycogen. Your muscles can call on these stores when your energy levels are low. So, it’s important to keep levels topped up and reserves in good supply.

Before activity

Before a run I’ll usually eat a meal or quick snack (depending on the time of day and my schedule), that’s rich in carbohydrates. For a snack I tend to opt for something like a banana or, if I have a quick break at work, I'll have Greek yoghurt with fruit and some granola. Both will add some simple carbohydrates that I can digest easily.

If I know I will be doing a longer run straight after work, I will have my lunch a little later and it will be carbohydrate heavy. This will give me enough energy and time to digest the food. For lunch I might have a pre-made spaghetti bolognese from tea the night before. Or if I haven't prepped any food, I might have a jacket potato with tuna and salad (with plenty of beetroot) from the local café.

I don’t want to feel uncomfortably full when working out, so as a rule of thumb I try to eat meals around 60-90 minutes before a workout. I can usually have a snack 20-40 minutes before. This is what works well for me, but it’s important to find out what works best for you and your training.

I usually run 10km in under an hour and find that this type of pre-workout sustenance suits my level of activity well. But if I up the intensity, for example if I’m aiming for a quicker time, or start to increase this distance in my training, I need to rethink my strategy. This usually involves upping the amount of carbohydrate-rich foods that I eat before my run. I’ll usually increase the volume of ‘complex carbohydrates’ such as brown pasta, rice and potatoes.

How much carbohydrate you should consume can get technical, with sources saying 10-12g per kg of body weight if you’re ‘loading up’ for a workout or run that will last longer than 90 minutes. For me, that would equal 1,080g of carbohydrate per day, which is a lot of food. For my training, I don’t need to carbohydrate load as such, because I’m not running regularly. A couple of times per week I will have an extra portion of carbohydrates. It could be two extra bagels at breakfast, an extra portion of rice or a couple of extra potatoes at tea. This works well for me, but the most important thing is to listen to your body and amend your strategy accordingly.

With any pre-workout snack or meal, I try to keep the fat and fibre content low as I find these foods harder to digest. For some people they may also cause tummy problems, which isn’t ideal – especially before the big race. I also find that certain types of pastas bloat me, making me feel lethargic and not in the mood for a run, so I avoid these where I can.

During activity – energy gels and sports drinks

If I notice that I’m flagging during my runs, I’ll start to think about refuelling along the way. For relatively ‘shorter’ more intense runs (around 45–75 mins) I’ll take in small amounts of a carbohydrate-rich sports drink. I may also do what’s called an oral mouth rinse. This is where I swill my mouth with a glucose-based drink and spit it back out as I’m running. It’s thought that carbohydrate in the mouth can stimulate the brain and nervous system and enhance performance just as it would if you drank it. One of the benefits of spitting out the drink is that you don’t consume extra calories. On race day it may also be preferable if the race provider has a different sponsored drink to the ones you’ve been using in training. Remember that it’s best not to try anything new on race day.

For longer runs (up to about two and a half hours), I’ll usually refuel with a sports drink or gel. For every hour that I’m running I want to get about 30–60g of carbohydrate. For reference, a 500ml (standard) bottle of sports drink from one popular brand contains around 30g. Gels fit nicely in your pocket, so make a convenient option when you’re out on your run. However, you might prefer to carry a bottle of sports drink with you. On race day, you may find the event organiser offers both, so you may not have to carry either.

There are lots of different types of gels. They have different amounts of carbohydrates in them, as well as different types of carbohydrates themselves. You can get some glucose only gels and others that contain a mix of glucose and another type of carbohydrate called fructose. For more information about what’s in your gel, read the information provided on your products packaging. And remember, find a type of carbohydrate mix and gel that works well for you. Some gels can give you an upset stomach, which is the last thing you want on a long run and others can have a funny consistency. Experiment with gels throughout your training and don’t leave it to chance on race day.

Refuelling and recovery

After training or a big race, I need to refuel and help my body to recover. I find it hard to eat a heavy meal straight after a run, so I tend to opt for a liquid-based snack. A glass of milk (skimmed or semi-skimmed) is a good post-exercise option. It contains lots of vitamins and minerals, protein and carbohydrates to help restore energy levels and help my muscles to recover. It’ll also help me to rehydrate – win, win!

When I’m ready, I’ll prep and eat my post-workout meal.

One of my favourites is this chicken and chorizo pasta meal, which provides a good combination of carbohydrates, protein and fats. It’ll also help me to reach my five-a-day, which will supply me with all the vitamins and minerals that I need.

Click on the icon below for more post-workout meal ideas (PDF 0.6MB).

Post-exercise meal plans

Here we’ve looked at how I eat to fuel my activity, but the tricky thing with nutrition is that everyone is different. Make sure you eat enough quality foods and stay hydrated – the rest is trial and error! My advice would be to go out for a run and take a banana with you one day and a gel the next, record what you did differently on each day and note down how you feel and how well you performed. Even include things like your mood prior to the run and the weather on the day. Recording all these things can help you to build-up a picture of what you need to perform well.

Finally, enjoy the exercise – above all, it should make you feel great!

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Adam Keenan
Adam Keenan
Health Adviser and sports enthusiast

    • Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic performance. J Acad Nutr Diet 2016; 116(3) pg 501-28
    • Nutrition for sport and exercise. British Nutrition Foundation., last reviewed December 2015
    • Food fact sheet: Sport. British Dietetic Association., published April 2017
    • Government Dietary Recommendations. Public Health England., published 2016
    • Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett Jr DR, Tudor-Locke C, Greer JL, Vezina J, Whitt-Glover MC, Leon AS. The Compendium of Physical Activities Tracking Guide. Healthy Lifestyles Research Center, College of Nursing & Health Innovation, Arizona State University. Retrieved September 2019
    • Lucozade sport orange 500ml. Sainsburys. www.sainsbury', accessed August 2019

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