Do I Need To Fuel During A Half Marathon?

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Running a half marathon, 13.1 miles or 21 km, is something beginner runners often set as a target.

However, it’s a tricky distance to prepare for. One of the great appeals of the Half is that it doesn’t have the enormous recovery period associated with a full marathon. And you won’t be forced to come face to face with ‘The Wall’.

But you still need to prepare well. And things can still go badly wrong on the day. One of the questions we get a lot is: do I need to fuel during a half marathon?

It’s possible to run a half marathon without fuelling along the way – but much will depend on your expected finish time. When we talk about a full marathon, everybody needs to fuel. The half marathon can be completed successfully without using energy gels – or even water – but most runners will find that it’s necessary to fuel along the way if they are going to be running for longer than 90 minutes.

There are no fixed rules regarding the fuel type, the amount of fuel when to take it, and if it is even necessary to fuel during a half marathon.

Therefore, every runner needs to be in tune with their bodies’ nutritional needs to help them determine the correct fueling plan.

Do Runners Need To Fuel During A Half Marathon?

Do I need to fuel during a half marathon?

The debate around the need for fueling during a half marathon is still ongoing.

However, fuelling may not even be necessary if you are a seasoned runner or if you can complete the race in a fast time (see our training pace calculator if you are unsure). On the other hand, beginner distance runners need to know all they can about fueling to finish their distance races.

Reasons for fueling during a half marathon include the following.

  • Muscles need fat and carbohydrates to provide enough fuel in the body to complete a long-distance race. Fat and carbohydrates fulfill different energy needs when running long distances.
  • Fat releases energy at a much slower rate than carbohydrates. Carbohydrates, also known as glycogen, stores energy within the muscles and releases it quickly to boost energy levels during a race.
  • On average, a runner can store up to 90 minutes’ worth of carbohydrates in the muscles before depletion. Therefore, runners that finish half marathon races in more than 90 minutes will need to refuel during their race to have enough energy to finish. Or at least… to do so comfortably.

How To Properly Fuel Before And During A Half Marathon

It’s interesting to note that proper fuelling starts way before the actual race.

Fueling starts during the training stages to help offset the toll of race day.

While training for a half mara, runners begin to understand their body’s fuel needs. During this time, they can adjust the type and timing of their fueling according to their needs.

Balance is the key word for most things. The same goes for nutrition while preparing to run a half marathon in the best possible time.

How To Properly Fuel Before A Half Marathon

Runners need enough calories to support the rise in activity during the training stages. An insufficient calorie intake will take a toll on all the training efforts. In addition, it reduces proper sleep, heightens stress levels, increases the risk of illness, and causes muscle loss. 

It is essential to ensure that the caloric intake matches the activity levels to ensure proper fueling during training. Doing this will provide better performance on race day.

Diet determines how long and hard you will be able to train and plays a significant role on the day of competing.

A healthy diet will contain nutrient-dense food that releases energy at regular intervals. Yes, junk food has many empty calories that can add numbers to your calorie count. Still, these empty calories deplete quickly, making it an unhealthy choice.

A healthy diet throughout training for the half marathon should include adequate healthy fats, fruit, vegetables, whole grains, and lean protein.

Eating tips for the week leading up to race day

  • Hydration is key. Start drinking two to three liters of fluid every day of the week before the race.
  • Avoid any caffeine for at least 48 hours before the race
  • Starting 48 hours before the race, consume 10g of decent quality carbohydrates for every kilogram of body weight. If you find this a problem, try using energy bars or drinks to add the necessary carbohydrates.
  • Avoid a big dinner the night before the race. Instead, have your more extensive dinner 2 nights before race day by adding an extra portion of rice, potatoes, or pasta to your meal. Enjoy a light pasta or risotto dish the night before to avoid bloating.
  • Replace proteins and fiber with carbohydrate-based meals to avoid discomfort during the race.
  • Smaller, high-quality carbohydrate-based meals, more often during the day, will serve you better starting 48 hours before the race than having fewer large meals. Taking smaller meals allows it to digest slower and store more energy.

How To Properly Fuel During A Half Marathon

Seasoned half marathon runners will advise you to condition your body during training. For example, your body should not rely so much on quick-releasing carbohydrates stored in the muscles but on the slower-releasing energy in body fat.

The reason is to condition the body to not only depend on the quick release energy from carbohydrates. Therefore, the fewer carbohydrates the body learns to get along without, the better for you on race day.

Eating Tips For Before Half Marathon Race Day

  • Enjoy a breakfast containing carbohydrates and a little protein one to four hours before the start of the race.
  • A pre-workout drink at the start line will be useful.
  • Replenish lost hydrolysates due to sweating at twenty-minute intervals.
  • Replenish your energy resources with thirty to sixty grams of carbohydrates every hour until finishing the race. Use sports drinks, sports bars, waffles, bananas, gels, and chews to achieve this. These foods will release muscle energy in a slow and steady stream.
  • Suggested post-race replenishments include having a sports drink, chocolate milk, and a protein bar. 

Warning To All Beginner Runners

Do not change or try anything new regarding fueling before race day that you have not tried during training. Changing anything last-minute about exercise or diet can potentially ruin your race altogether.

The key to success is to find what works for you and following the exercise program and diet diligently will produce results.

Should I Fuel During A Half Marathon?

If you can complete a half marathon in under 90 minutes, you are already a very accomplished runner and chances are you can complete the race before your body actually needs the additional fuel.

If you are intending to complete the Half in 90 to 120 minutes, it’s a judgement call that should be made based on your experience fuelling during similar training runs.

If you are likely to take over 120 minutes to finish the race – yes, we strongly advise you re-fuel along the way.

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Alex Randall

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Alex is the editor at Revel Sports. It was his idea to take our post-club-run chats and build a website out of them. He is responsible for dotting the I’s and crossing the T’s when any of us have something to post. (Basically: it’s all his fault). A ferocious 5K powerhouse on his day, Alex is known for not understanding the meaning of the term ‘negative split‘.
Alex Randall

Revel SPorts Contributor

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