How to fuel a long run is a question I get asked all the time as a runner’s nutrition coach, or a variation of it at least. But before we jump in let’s address why fuelling a run is essential. Assuming our muscles are fully stocked with carbohydrates, in the form of glycogen, we have enough energy stored to last between 60-90 minutes. Once we run out of glycogen our body switches to fat which is slower to convert and the reason we hit the wall. So by ensuring we fuel our runs, we are making sure we have enough energy so we don’t hit the wall, it also improves our performance and can help us recover faster afterwards. All things that are so important when training for an event where we really want that personal best.

For this post we are considering a long run to be anything over 60 minutes, this is because anything under 60 minutes we don’t need to consume fuel on the go. We’re going to be looking at the hydration and nutritional strategies required to maximise performance and energy during your long run.

Pre-Run Nutrition: Laying the Foundation

Fuelling a long run starts before we lace up our trainers and hit the streets. Most runners (not all) will be doing their long runs in the morning. So you have been to sleep and have fasted for somewhere between 8-12 hours. Our body will have used some of the carbohydrates you consumed with dinner last night so replacing these and ensuring our glycogen stores are full is going to be important.

Timing your pre-run meal

You want to eat somewhere between 2-4 hours before you plan to run. This is to allow time for the food to be digested and processed within our bodies, so the fuel is available to us and ready to use. All this takes a little bit of time.

What to eat

You want to focus on carbohydrates with a little protein before running, minimising high-fat foods and fibre as these can cause GI issues.

Some great options include:

• Oatmeal/porridge with fruit
• Bagel with peanut butter
• Toast and jam

Hydrating before you run

Ensuring you are hydrated before getting out for your long run is also important. If you are running in the morning you are likely to have become a little dehydrated overnight. As such we want to ensure proper hydration. In the couple of hours leading up to the run sip on water or an electrolyte drink. Aim for around 500mls as a rough guide.

During the Run: Maintaining Energy Levels

The next stage is the what and when during the run. You might think but if I started my run fully stocked with glycogen and I’m only going out for 90 minutes why do I need to fuel? It’s a good question, the point of fuelling during a run is to maintain energy levels. But it also serves other purposes such as training our gut for when race day comes about and helping with recovery afterwards. The point is not to deplete our energy stores on our runs but to maintain them so we can stay consistent and perform at our best.

When to start fuelling

You don’t want to wait until you are close to or have run out of energy. So we want to start fuelling early and often. Generally speaking, this will be within the first 30 minutes but definitely within the first 40 minutes. This is so that anything we consume is digested and has been absorbed before our body needs the fuel. Waiting too long means you’ll hit the wall before the energy consumed is able to be used by the body.

What to use for mid-run fuel

There are 2 main types here sport-specific products or ‘real’ food

Some sports products include

• Gels
• Chews
• Sports drinks

Some ‘real’ food alternatives include

• Dates
• Fruit puree pouches
• Flapjack

There is no right or wrong here with what you choose, gels can be easy to take because they don’t require any chewing. But some people just don’t like the taste or texture of them.

How much do you need?

• If you are running for 1-3 hours aim for 30-60g carbohydrates per hour
• If you are running for 3 hours + aim for 60-90g carbohydrates per hour

Hydration and electrolytes

Staying hydrated is important as once you get dehydrated your performance can start to suffer and it can lead to symptoms such as headaches and nausea. The average sweat rate is between 0.5-1.7l per hour, I know this is a big range so how much should you drink?

Aim for between 50-250ml per 20 minutes, this is going to depend on the weather and how sweaty a runner you are. For heavy sweaters or hotter conditions aim for the top end, for light sweaters or colder conditions then you could aim for the lower rate.

What about electrolytes? The main electrolytes are sodium, potassium and magnesium and their role is to help our body keep the water we need, as opposed to peeing it out. So electrolytes help maintain a water balance within the body and help us stay hydrated. Again sodium loss varies a lot from athlete to athlete but the average is around 950mg/l. So aim to replace at least some of this while running.

Post-Run Nutrition: Recovery for Next Time

So you’ve finished your run and now probably just want to collapse on the floor and do nothing. I mean that’s totally cool but grabbing yourself a recovery snack or drink on the way will really help. Your body has just allowed you to run so it’s time to show some thanks and replenish the fuel you have used. This can help speed up recovery, help prevent injury and can help muscles feel less sore. 

Timing of Recovery Nutrition

You want to consume something within an hour of finishing your run. But if you can do this within 30 minutes then even better. I know what you’re thinking, Rachel I just finished a run I want to sit down, maybe take a shower, stretch (some runners do), take a nap etc I do not want to be making myself something to eat. Trust me I am with you on this as such my go-to immediately after a run recovery snack is either a glass of chocolate milk or a smoothie/shake. By opting for something like this it is quick, easy, and can be consumed while you do all the things when you get back from your run.

Key Nutrients for Recovery

Carbohydrates: are a must, you have been using your glycogen stores, and even with taking on fuel during the run you still need to replenish them.

Protein: Endurance running can cause little micro-tears to our muscles, which is a good thing as it helps with adaptation, protein helps the recovery and repair of these so we want to include this as well.

Examples:

• Smoothie with Greek yoghurt/protein powder, fruit and maybe some oats
• Greek yoghurt, berries and granola with a drizzle of honey
• Chicken with quinoa and vegetables/salad

Rehydration

The chances are you have lost more fluid than you have been able to replace while running so ensuring you rehydrate is going to be key. Dehydration following a run is a cause of things like headaches and nausea. You want to replace all the lost fluid, again consuming electrolytes is more effective in rehydrating than just plain water. So adding electrolytes to your drink will help.

Common Fueling Mistakes to Avoid

Here are some of the biggest mistakes I see when it comes to fuelling

• Underestimating fuelling needs so not taking on enough
• Not drinking enough on runs, especially in the colder months
• Waiting too long before taking on fuel, so running out of energy before it can be replaced

Tailoring Your Fueling Strategy

There is no one-size-fits-all when it comes to the topic of how to fuel a long run. There are also a lot of factors that impact what is going to be the right strategy for you. So here are my top tips for tailoring your fuelling strategy:

1. Experiment with different fuel types
2. Little and often, this is for both fuel and hydration
3. Check the weather forecast the day before or a couple of days before so you can plan
4. Keep a log of what worked/didn’t work
5. If you’re training for a race see what is available at water stations and try this out in your training

Conclusion

• Fuelling your long run starts with what you eat before your run
• Get a carb-based meal in 2-4 hours before running
• Start fuelling early in your run
• Don’t ignore hydration
• Start refuelling as early after your run as you can, a glass of flavoured milk is perfect as it contains protein, carbs, fluid and electrolytes
• Take electrolytes to help you stay hydrated
• Most importantly if you are training for a race use your long runs to practice your fuelling and hydration strategies

What to know about fuelling your runs? Then download my free guide The Ultimate Fuelling Guide for Runners it contains both pre and post-run meal and snack ideas along with mid-run fuelling advice.

Want more personalised support to fuel your running? Then join Fuel & Thrive now, a 12-week program specifically designed to help runners simplify their nutrition while increasing endurance and energy levels. 

My go-to electrolytes are these by precision hydration