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Whether you’re a seasoned marathoner or a beginner runner, knowing when to take energy gels can make a significant difference in your performance and endurance. Energy gels are a convenient source of quick, easily digestible energy, but timing is key. To help you understand this better, we’ve compiled a quick FAQ addressing the most common questions about energy gel consumption.

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1. When should I take an energy gel during a run?

As a general rule, you should take your first energy gel 30-45 minutes into your run, and then every 30-45 minutes thereafter. However, this can vary depending on your body weight, pace, and the intensity of the run.

2. How often should I take energy gels during a marathon?

For a marathon, a good guideline is to consume 1g of carbohydrates per kilogram of body weight per hour. This equates to about 2-3 energy gels per hour for a 60-kg athlete.

3. Can I take an energy gel before a run?

Yes, taking an energy gel before a run can provide a quick source of energy. However, it’s generally recommended to have a carbohydrate-rich meal 2-3 hours before the run for sustained energy.

4. When should I take energy gels for a long-distance run or race?

For long-distance runs or races, it’s crucial to maintain your glycogen levels. Start taking energy gels 30-45 minutes into the run and continue at regular intervals. Be strategic and consider the course – you might want to take a gel shortly before a challenging climb, for example.

5. What happens if I take too many energy gels at once?

Taking too many energy gels at once can spike your blood sugar and may cause gastrointestinal distress. It’s better to space out your energy gel consumption throughout your run.

Remember, these are general guidelines and individual needs can vary. It’s important to practice your fueling strategy during your training runs to find what works best for you. Now, let’s dive deeper into the science and strategy of energy gel consumption.

Energy gels as everyday fuel vs. race fuel

Energy gels are typically categorized as race fuel since most amateurs and weekend warriors can’t stomach energy gels every single day, and there’s no reason to, in my humble opinion.

A daily dosage of gooey sugar water is definitely not what anyone would call a healthy diet.

However, I recommend you pick a few workouts that closely simulate your race to practice fueling with energy gels. If you are a marathon runner, it might be a 30km progression run on a Saturday morning. For an ironman hopeful, it could be that 100km ride to break in your ass.

You probably don’t need energy gels if your race is under an hour. A carbohydrate-rich breakfast at least 2 hours before the start should suffice.

How long does it take for an energy gel to work?

Although many energy gels market themselves with buzz words like “instant boost” or “fast-reacting,” it takes time. Your body’s various mechanisms need time to break down the nutrients into “energy” that propels you forward. Some athletes say they feel a boost within 5 minutes, and some say it takes up to 15-20 minutes.

If we get into the nitty-gritty of it all, gel ingredients, how fueled up you are at the start, exertion intensity, and hydration all play a role.

During exercise, blood is diverted from your stomach to muscles and cooling mechanisms, meaning carbohydrate digestion and absorption are compromised. Give your digestive system and muscles ample time to do what needs to be done to fuel up. We all absorb carbohydrates differently, so once again, practice makes perfect.

Take an energy gel before you truly need it and definitely way before your body sends out the “bonking very soon” alert. The key takeaway here is prevention is better than cure.

start of a marathon
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How often should you take an energy gel?

As covered in detail in our gel-ingredients article, there’s a limit to how much glycogen your liver and muscles can store. So fueling regularly during a race is crucial to maintain your glycogen level. Most energy gels provide between 20-30g of carbohydrates, so let’s use marathon running as a reference. A fit runner can store between 90-120 minutes worth of glycogen going at marathon to near lactic threshold pace.

Here’s a simple guide. Consume 1g of carbohydrates per kilogram of body weight per hour, meaning a 60-kg athlete should take in 60g of carbohydrates each hour, about 2-3 energy gels.

If you had a carbohydrate-rich breakfast 2-3 hours before the race, you should be fairly fueled up at the start line. Take your first gel 30-45 minutes after the gun, and it goes without saying that remember to evenly space out the energy gels afterward. Taking two or three at a time spikes blood sugar and may cause gastrointestinal distress. An upset stomach can seriously derail your race.

Another common cause of stomach discomfort is taking energy gels without water. Remember to drink 250-300 ml of water per packet.

Here’s a pro tip! Squeeze energy gels into your water bottle following the 1 packet-to-250 milliliters ratio. This is a great way to steadily replenish glycogen and fluids throughout the race.

Be strategic with energy gel intake

Whether its ultra running, a triathlon, or a big day on the bike, you can be more strategic with energy gels if you are familiar with the course. Slam down an energy gel 5 minutes prior to a long climb, or if it looks like it may come down to a sprint finish, plan ahead for the increased effort.

Gels as energy for the brain

Many athletes noted that they experience an energy surge as soon as the gel hits their mouth, way before their digestive systems can process the carbohydrates.

The reason is the taste of energy gels sends a signal to your brain – FRESH ENERGY INCOMING! – to prime the body to process the carbohydrates. In anticipation of the refueling, your mind often delivers a performance boost in advance.


Energy gels can also wake you up and provide moments of clarity when fatigued because the human brain runs on the glycogen stored in the liver.

Just like training, race fueling is more art than an exact science. Find out what works for you by listening to your body. With an over-reliance on gadgets and data, you have to relearn what should have been natural instinct. Practice, learn from your mistakes, and repeat to nail your race-day fueling with energy gels.