On long runs, you will need to consume food on the go. What to eat and how much to eat will be different for each runner and will depend on multiple factors. This article serves as a rough guide, but each runner will need to experiment to work out what works best for them.
Eating while running
When you run, your body consumes stored carbohydrates as well as some fat. The ratio of carbohydrates to fats depends primarily on the intensity of the activity. However, your body can only store a limited amount of carbohydrate and it usually runs out after about 90 minutes of intense activity. Whatever your intensity or ability to burn fat, you will still need to replenish your carbohydrates after roughly 90 minutes. If you don't replenish the carbohydrates, your performance will suffer. Your body will force you to slow down and will burn relatively less carbohydrate and more fat.
So, if your run is shorter than 90 minutes, you can get away with not eating, and just replenishing after your run. But if you are running longer, you'll need to eat along the way.
When you run, you burn calories faster than you can take them in. The average runner can digest somewhere between 150 and 300 calories per hour, depending on multiple factors such as effort, body mass, type of food, climate and more. And, you'll burn somewhere between 600 and 1000 calories per hour depending on pace, body mass, terrain, and more.
The idea is to give your body just enough food so it's not starved of carbohydrates, but not more than you can digest. Too much food will weigh you down and lead to gastrointestinal issues. Don't try to eat as many calories as you're burning, or you'll have a bad day.
The general rule is to start taking in calories after about 30 minutes and continue to take in about 100 calories every 30 minutes or so. Obviously, this will vary based on the individual and a multitude of factors. It's important to experiment during your training runs to work out what works best for you.
What to eat when running
So, you know roughly how much to eat while running. Now to work out what to eat.
The macronutrients that make up foods are carbohydrate, fat, and protein. For running, carbohydrates are the important ones and generally, you'll be looking for food high in carbohydrates, although fat and protein shouldn't be ignored.
Carbohydrates include sugars, starches and fibres. They're classified into simple and complex carbohydrates. Simple carbohydrates contain just one (monosaccharides) or two sugars (disaccharides), such as fructose (from fruits) and galactose (from milk products). Complex carbohydrates (polysaccharides) have three or more sugars. They are often referred to as starchy foods and include beans, peas, lentils, potatoes, and whole grains. As a product of digestion, complex carbohydrates are broken down into simple sugars.
Another important class of nutrients for running is salts. Sodium is probably the most important, but potassium and magnesium also play a role. These are important for muscle and nerve function, pH and fluid balance.
You should also consider how portable a food is for trail running. It'll need to go in your pack and will be subjected to constant jiggling for kilometre after kilometre.
Why real food?
I'm not a big fan of gels and sugary drinks for race nutrition or for long training runs. I much prefer using real food. For me, it sits better in my stomach and feels better in general. It's also a lot more palatable and doesn't lead to a litter problem.
However, as I already mentioned, eating while running is a highly personalised thing. Some people might only be able to handle a very specific foods and some might not be able to handle any solid food at all.
You can get away with eating just about anything when running. Take in as many guilt free donuts as you can. The most important thing is getting the calories in and keeping them in.
So here is my list of real foods for trail running, which may also be useful for long distance running and endurance sports in general.
Bought and ready to eat
These foods don't require any preparation, other than stowing into your pack. These are good if you're just starting out or if you're in a hurry. Also, if you find yourself out on a long run with a credit card, you can just pop into a nearby store and pick up some of these to keep you going.
Bars: This is a very broad category and includes a wide range of products. Try to pick bars that aren't too high in refined sugars and are made from whole grains.
Chips (crisps): These are great when you feel like a bit of salt. They're really light in your pack. Just go for plain flavours as the spicy ones might not sit well.
Nuts: Nuts are a great combination of protein, carbs, and fat. Choose your nut based on the macronutrient profile. Don't over-do the nuts though. They can feel a bit heavy in the stomach sometimes.
Fruit: Some fruits are better than others. Bananas are a common favourite. I also like apples. Be careful with fruits that are high in fibre. Some of my favourites:
- orange (pre-peeled or be prepared to get sticky)
Dried fruit: These are a bit more portable than fresh fruit. As with fresh fruit, be careful with fruits high in fibre if you're sensitive. Just experiment with what works for you. Some favourites are:
Pretzels: Nice for a bit of salty starch. Easy to pack and quite light. Some people find them a bit dry though.
Junk food: Things like doughnuts, tarts, biscuits (cookies), pizza, and lollies (candy) are all valid foods during a long event. Whatever you need to do to get the calories in.
Requiring some advance preparation/cooking
If you want to get serious, preparing your own running snacks is the way to go. You'll know exactly what's in them and you can tailor them to your specific requirements and desires.
Boiled potatoes: If you can get baby potatoes, just boil and salt them. If you can only get large ones, they can be cooked, oiled and salted. You can also mash them and put them in a pouch.
Wraps: can be filled with just about anything, but here are some suggestions:
- peanut butter and jam (or banana)
- almond butter, banana, honey (+ soy sauce for salt if you want to go crazy). I think I heard this one recommended by Dean Karnazes.
- nutella and dried fruit
Croissant: Fill them with just about anything. Cheese, jam, nut butter, etc are all good options.
Fruit cake: Either homemade or bought. Cut into nice sized chunks and put into plastic sandwich bags.
Water: My preferred hydration option. If you want hydration, water is the original and the best.
Coconut water: Coconut water is full of handy electrolytes and some people live the taste. I've tried it but it didn't work for my tastebuds.
Iced tea with honey: Honey contains potassium, which is an important salt for muscle function. Honey is also a good source of antioxidants.
Fruit juice: Provides a nice little sugar kick. Use with caution. Can be hard for some people to stomach.
Cold brewed coffee: I've seen this at a couple of events, and it's surprisingly refreshing. The caffeine hit may also be desirable in the late stages of an event.
Chocolate milk: You'll need to keep it cold, maybe by freezing it in a pouch, but chocolate milk is great to keep you going during a long run, and some people swear by it for recovery.
Flat Coke: Some people swear by flat coke for a bit of caffeine and a sugar kick. I haven't had Coke for years, though so I wouldn't recommend it. Other flat soft drinks would also be an option.
Baby food: If you get it in those squeezy pouches, it's really portable and easy to digest.
Honey: A bit tricky to get into a pouch, but packed full of energy. You can also buy honey in little disposable pouches, but then you end up with a litter problem.
Home made gels: You can make your own gels, like these.
Pouch recipes: You can make your own semi-liquid creations to fill squeezy pouches. The No Meat Athlete has a collection of great recipes, including these:
- Salty Sweet Potato
- Pina Colada
- Maple Cinnamon Oatmeal
- Apple Maca
- Banana Maca
- Chia Switchel
Please let me know your favourite running snacks. I'm sure there's a heap of stuff I've left out.