- Supplementing during a half marathon is critical because glycogen stores are depleted after about 75 to 90 minutes. Without proper refueling, you risk a drop in energy that could compromise the race.
- The best foods for replenishment are simple carbohydrates: energy gels, gummies, isotonic drinks, or dried and fresh fruits. It is important to test them first in training to avoid digestive problems.
- Timing of supplementation is crucial: start before you feel the need, taking the first supply after 30-45 minutes and continuing every 30-40 minutes to maintain a stable energy level.
When you decide to train for a half marathon, there are many aspects you need to consider: your training plan, your race strategy, the right clothing and shoes for you, and, last but not least, one of the most important: nutrition.
On shorter races, such as a 5 or 10K, there is no need to supplement over the course of the race. Running the 21km half marathon is a whole different story: managing energy becomes critical to avoid “hitting the wall” and getting to the finish line without collapsing.
So the answer is yes, supplementing over the course of a half marathon is necessary, if not essential. However, how and how much you should supplement depends on various factors, such as your pace and estimated race time.
Why is it important to integrate over the course of a half marathon?
Every time you run, your muscles consume energy in the form of carbohydrates and fats. The “problem” is that carbohydrates, which are the main energy source for intense efforts, are limited in our bodies. Glycogen stores (the fuel stored in the muscles and liver) can last roughly between 75 and 90 minutes. This means that if you plan to finish the race in more than 75 to 90 minutes, as most of us do, you will probably need extra help to be able to maintain the pace and not feel fatigue set in. The slower you run the more important refueling becomes because your race will last longer and you will gradually use up your energy reserves.
What to eat during a half marathon?
The best source of energy is simple carbohydrates, which are easy to digest and quickly available to muscles. Okay but so what? What you need to get are:
- energy gels;
- gummy candies, which have become very popular recently;
- isotonic drinks;
- dried fruits such as dates, raisins or apricots;
- fresh fruit such as banana or apple puree in sachet form.
Energy gels are among the most popular options because they are practical and quick to consume. However, it’s important to test them in training to ensure they don’t cause stomach issues.
If you plan to use aid stations along the route, check in advance what they will provide to ensure it matches what you have trained with, avoiding unpleasant surprises on race day.
When to take supplements during the race?
The best strategy is to start before you actually feel the need. Waiting until you run out of energy may already be too late. A general guideline is:
- take the first one after 30-45 minutes of the race;
- continue to supplement every 30 to 40 minutes, depending on the estimated duration of the run;
- consider taking a gel about 20 minutes before departure to leave with a good supply of energy.
The amount of carbohydrate intake varies according to body weight. A simple formula is 1 gram of carbohydrate per kilogram of body weight per hour. So if you weigh 60 kilograms, you should aim for about 60 grams of carbohydrates per hour of running, equivalent to about two energy gels, depending on their dosage.
Always test your strategy before race day
The number one rule to avoid problems during the race is to test everything in training. This applies to your clothing, shoes, and supplements. Try different types of foods and timing strategies during your long runs. That way, on race day, you’ll know exactly what works for you and can focus solely on running.