What to eat before a race for peak performance? (#91)

What you eat before a competition is one of the most debated topics in sports nutrition, with advice varying widely. This article clarifies what's actually important and what's mostly myth. Based on current research, we consider how the content of your meal, its timing, and your individual response affect your performance. The emerging picture is clear: details like the glycemic index matter less than many think, whereas the big picture – ensuring you have energy available and a strategy that suits you – is crucial. The conclusion is that you don't need to complicate things, but you should test and adjust your fueling to perform at your best.

The topic of eating before a race is a hotly debated area!

“You don’t need to eat anything before a race”
“Watch out for fast carbs so you don’t crash after the start due to low blood sugar”

These are two common statements most of us have heard at some point in connection with a race. When it comes to how you can and should think about nutrition before a race, opinions vary just as widely as breakfast choices—from those who advocate running on an empty stomach to those who start fueling with energy as soon as they open their eyes. Here, we explore what research has revealed about what you should eat before a race.

What to eat before a race is a popular topic, and athletes are often advised to choose foods with a low GI (glycemic index). The concept behind a low-GI meal before an event is that it reduces the risk of sudden, rapid increases in insulin release, helping to prevent a blood sugar crash right before starting. The goal is also to ensure that insulin spikes don't interfere with fat oxidation before the event.

The whole concept is attractive, but specific positive effects on athletic performance compared to those consuming a high-GI meal have not been conclusively proven.

Here you can learn more at the National Food Agency about GI & GL:

But, is there any consolidated research that can break it down into practical tips for you as an athlete?

Yes — fortunately, a new systematic review and meta-analysis was published in June 2017. The study is titled "Effect of Glycemic Index of a Pre-exercise Meal on Endurance Exercise Performance: A Systematic Review and Meta-analysis" and includes 19 studies where researchers primarily wanted to find out:

• How does the glycemic index of a meal affect the performance of well-trained athletes when consumed before activity.

A couple of secondary questions were:

1. The effect of the timing of the meal
2. The size of the meal
3. What are the outcomes if participants also consume energy during activity

It's simply a study packed with relevant and intriguing data for you as an athlete.

1. Whether the meal has a high or low GI probably doesn't matter much, regardless of whether athletes consumed energy during the activity. However, there was a tendency for a low-GI meal to be beneficial if participants didn't consume energy during the session.
2. Maintaining glycogen stores as much as possible during the activity should always be the priority. Consuming energy during the activity is thus more crucial than exactly what you eat beforehand. If you have a history of gut issues before performance, it may be more important to focus on intake during the race rather than trying to optimize the pre-start meal.
3. If you compete in a sport where acquiring energy during the activity is difficult, you might need to place extra emphasis on the pre-race meal. As mentioned in the article "mouth rinse", the effects of intake during activity are minimal if your stores are full beforehand and the activity is short. Therefore, there are several ways to consider this. If you're one of those athletes who find it challenging to eat before activity and also have difficulty taking in energy during it, a mouth rinse could be worth trying.

A couple of years ago, Asker Jeukendrup and Sophie Killer published the study "The Myths Surrounding Pre-Exercise Carbohydrate Feeding".

In that study, they explore, among other things, the experience of low blood sugar that some participants reported during their studies in the 2000s. It turned out that what primarily correlated was not when the participants consumed the energy, but which participants were examined — indicating a significant individual factor at play. The athletes who experienced feelings of low blood sugar after consuming fast carbohydrates 45 and 75 minutes before activity were consistently the same ones. This was despite not having blood sugar levels indicative of hypoglycemia. These participants experienced fewer symptoms when they consumed energy as close as 15 minutes before the activity.

If you're someone who experiences energy dips, here are a few things you can try:

1. Consume a meal or energy at least 90 minutes before your performance. The amount of energy doesn't seem to make much difference.
2. Take in energy as late as 15 minutes before activity to avoid the feeling of low blood sugar.
3. Consume energy with a low GI.

What to eat before a race is a frequently debated topic, regardless of what research reveals. The reasons are numerous, but one of them is that participants can exhibit symptoms of low blood sugar even when their levels aren't actually low. So, we need to be flexible in our recommendations.

In measurable terms, whether the meal has a high or low GI makes little impact on your performance. Maintaining glycogen stores should always be the priority, which is why intake during activity is often most important. If you have a fairly stable gut, we recommend having a light breakfast similar to what you're accustomed to, and consuming 20–30 g of fast carbohydrates during the activity or as close as 15 minutes before the start—provided you've tested this and your stomach can handle it.

If you need to perform very early in the morning, you don’t need to wake up extra early to have breakfast; you can often do well with a little quick energy just before, as long as you also consume energy during the activity according to recommendations and have tested that your gut tolerates it.

However, if you're performing later in the day or around lunchtime, like at the Göteborgsvarvet race, it may be important to eat a larger and more balanced breakfast to sustain energy before your performance.