A good snack before interval running is about easily digestible carbohydrates, appropriate timing, and a stomach that feels calm.
- Ideally, eat a regular meal 2–3 hours before intervals and a smaller snack 30–60 minutes before the start.
- For many, around 20–40 grams of carbohydrate before an interval session works well, depending on the length and intensity of the workout.
- Choose snacks with carbohydrates and a low content of fat and fiber, for example a banana, white bread, rice cakes, or an energy bar.
- Test the snack and timing on regular training sessions so you know what your stomach tolerates well.
Intervals can be an effective way to work on fitness and speed, but that assumes you show up with adequate energy. An appropriate snack before interval running can help support that you can complete the session as planned while also reducing the risk of stomach discomfort.
Here you’ll get a practical guide to what you can eat 30–60 minutes before intervals, how much typically works for many people, and how you can reduce the risk of a heavy stomach. You’ll get concrete snack ideas and simple rules of thumb you can try in your own training.
Why intervals require a well-thought-out snack
Intervals sit high on the intensity scale. Your heart rate rises, the pace is high, and the body relies heavily on muscle glycogen—carbohydrate stores in the muscles.
If you show up for intervals with low energy stores or without a plan for what you eat beforehand, you may experience, among other things:
- Your legs feeling heavy already after the first repetitions
- It becoming difficult to keep the pace steady throughout the session
- Stomach discomfort if you have eaten too heavily or too late
The purpose of a snack before interval running is therefore typically not to eat a large meal, but to get a small amount of easily digestible carbohydrates that can help support performance during the session without unnecessary stomach upset.
How to time your meal and snack before intervals
It’s often an advantage to think in two steps: first a main meal, then a smaller snack closer to the start.
Two to three hours before intervals
For many, it makes sense to have a regular meal that:
- Contains carbohydrates, for example oatmeal, pasta, rice, potatoes, or white bread
- Has a moderate amount of protein, for example chicken, fish, eggs, or yogurt
- Is not very heavy in fat and fiber, so your stomach typically feels calmer when you have to run
Concrete examples could be:
- Oatmeal with banana and a spoonful of skyr
- Rice with a bit of chicken and tomato sauce
- White bread with lean cold cuts and fruit on the side
Thirty to sixty minutes before interval running
In the time right before, many runners choose a smaller snack focusing on easily digestible carbohydrates and a low content of fat and fiber.
A practical rule of thumb is about 20–40 grams of carbohydrate for many, depending on body size, intensity, and duration.
If you have a sensitive stomach, or very short and hard intervals are on the program, it may work better for some to have the snack around 45–60 minutes before and choose a smaller amount.
Examples of good snacks before intervals
A snack before interval running is typically:
- High in carbohydrates
- Relatively low in fat and fiber
- Something you know and tolerate well
- Small enough that you don’t feel heavy
Snack ideas 30–60 minutes before intervals
- A banana, optionally with a small handful of raisins
- A slice of white toast with a little jam or honey
- One to two rice cakes with jam or banana slices
- A small bowl of thin oatmeal made with water or low-fat milk, without lots of nuts and seeds
- A small energy bar or energy snack that is primarily carbohydrate and low in fat and fiber
For many runners, it can be practical to use a sports bar that is designed to be easy to eat before and possibly during training. PurePower’s own Energy Snack energy bars for before training, for example, are based on, among other things, oats and glucose syrup and can be used as a carbohydrate source before training in a soft consistency that for many is easy to get down.
If you want to find a flavor you like and typically tolerate well for your intervals, you can, for example, try an Energy Snack Sample Mix, where you get one of each variant to test in training.
How much snack is often sufficient
Most recreational athletes don’t need large amounts of food right before an interval session. Too much food close to the start can, for some, cause a heavy feeling and stomach issues.
A simple guideline can be:
- Shorter sessions, for example six to eight times 400 meters and total duration under 60 minutes: A small snack of about 20–30 grams of carbohydrate 30–60 minutes before. This could be, for example, a banana or half to a whole Energy Snack.
- Longer or particularly demanding sessions, for example five times 1000 meters, ten times 400 meters, or VO2max training totaling 60–90 minutes: A snack of about 30–40 grams of carbohydrate, possibly a bit earlier, around 45–60 minutes before, so your stomach has more time.
If your focus is weight loss, you can still plan a small snack, but choose the lower end of the range. At the same time, it’s worth remembering that adequate energy intake can help support the quality of your training over time.
What you may want to avoid before interval running
Stomach problems during intervals rarely come down to one single product, but often to the pattern of what and when you eat. Many runners experience fewer issues by cutting back on the following close to training:
- High fiber content from, for example, rye bread, very whole-grain bread, beans, lentils, large amounts of vegetables, and cabbage right before hard running workouts
- Very fatty food such as large amounts of nuts, cheese, rich sauces, deep-fried foods, and fast food close to the start, which typically takes longer to digest
- Very large portions, for example a big meal one to one and a half hours before intervals, which can cause discomfort and the feeling of running on a full stomach
- New products on key training sessions, where snacks, gels, or drinks are tried for the first time on a hard interval workout instead of on easy runs
If you struggle with solid food close to training, drinkable options can be an alternative. This could be smoothies, juice, or a carbohydrate-containing sports drink. Here, an energy drink with carbohydrates in your bottle can be a simple way to get carbohydrates without having to chew.
Fluids and electrolytes before hard intervals
Beyond the snack itself, fluid balance plays a significant role in how a hard session can feel.
A practical model that many use looks like this:
- Drink about 400–600 milliliters of fluids over the last 1.5 to 2 hours before training
- Take small sips as thirst dictates in the minutes leading up to and during the warm-up
- Avoid downing a whole bottle right before the start, as for many this can cause a sloshing stomach
On hot days, with heavy sweating, or during extra-long sessions, it may be relevant to supplement with minerals and salts. Electrolytes for fluid balance in your bottle can be used to help contribute to normal fluid balance as part of a varied diet and healthy lifestyle.
If you want to combine carbohydrates and fluids in one solution, you can use an isotonic drink or an energy powder so you get fluids and carbohydrates in the same bottle.
Solutions if you train early or aren’t hungry
There are especially two situations where the snack before intervals can be challenging in practice.
Morning intervals
If you have to run very early, fitting in a large meal two to three hours before can be hard. In that situation, you can:
- Make sure to have a carbohydrate-rich dinner the day before
- Have a small snack, for example a banana or half an Energy Snack, 20–30 minutes before
- Optionally supplement with some carbohydrate in your bottle, for example a sports drink or energy powder
When you find it hard to chew close to hard training
If it feels uncomfortable to eat solid food right before, soft or liquid options may work better:
- Smoothie or thin yogurt and drinking yogurt
- Juice or cordial
- Carbohydrate sports drink
- A small amount of energy gels for quick carbohydrates or energy chews gummy candy, if you do better with those formats than with bars
Regardless of the solution, the point is the same: Use your regular training sessions to find out what your stomach tolerates well, so you have a routine you’ve tested when you’re facing hard intervals.
Common mistakes before interval running and simple adjustments
Here’s a short checklist you can use the next time you plan an interval session.
- Mistake 1: You eat too much, too close to the start. Solution: Move the main meal to two to three hours before, and stick to a small snack 30–60 minutes before.
- Mistake 2: You choose very coarse, fiber-rich bread and vegetables. Solution: Use lighter carbohydrate sources like white bread, rice, pasta, and banana close to hard training.
- Mistake 3: You test new snacks and supplements on a hard session. Solution: Try new products on easy runs or shorter sessions so you can see how your stomach responds.
- Mistake 4: You forget fluids or drink far too much right before the start. Solution: Plan your fluid intake over the last couple of hours before training and take small sips around the warm-up. Consider electrolytes when it’s hot or you sweat a lot.
- Mistake 5: You show up completely fasted for long, hard intervals. Solution: Make sure you have a carbohydrate-rich meal earlier in the day and/or a small snack closer to the start, especially when the session approaches an hour or more.
If you want to dive deeper into how meals and snacks before training can be planned, you can read more in our article about what to eat before training. Many of the principles for timing and snack choice apply, whether you’re cycling long distances or running intervals.
Everything in this guide is general guidance. Your body, your stomach, and your daily life are different, and needs can vary. Test and adjust, and find the snack and timing that works best for you in practice.