LOLZletter Edition 28| Fueling While Running


Today is the 28th edition of the newsletter. When I asked Instagram what they would like to read about this week, many people suggested fuel.

Keep in mind, I’m not a nutritionist or dietitian. I do have a public health degree, but that doesn’t make me an expert. Finally, every person is different. Just because X can run a marathon on two gels doesn’t mean Y doesn’t need four.

As for me: I have a full breakfast (coffee, waffle, and peanut butter) before and four gels during a marathon. I also hate running on an empty stomach.

What’s the deal with gels and “fuel” anyway?

When you run fast, you use carbohydrates. Once you run out of a carbohydrate source, you’ll be forced to slow down. This is often what people refer to as “hitting the wall” or “bonking.” It doesn’t have to be during a marathon; you can hit the wall during any distance.

Instead of linking to what is keeping me entertained this week, here are a few great, science-based reads about fueling, particularly about taking in carbohydrates:

High-Quality Carbohydrates and Physical Performance

Carbohydrates – The Master Fuel

Three things runners need to know about carbs

After about 60 minutes of exercise, your body starts needing carbohydrates.  

During 60+ minutes of running (whether it’s a 10K or marathon), carbohydrates are your primary source of fuel. The body cannot physically store enough carbs to last an entire marathon (we are not camels).

First, it’s vital to start a distance event “with a full tank." Then during the race, the energy sources, whether you prefer gels, Gatorade, or a peanut butter sandwich, act to "top off."

When you continue to top off your tank with high-energy fuel, you can maintain the pace and speed you are running. If you do not top off your tank, you may be able to continue running, but it will be slower. Both fat and protein can eventually be broken down into energy, but it won’t be high energy like what you get from carbohydrates.

Carbs are stored in the liver and muscles, but your race performance actually relies more on the carbs (and glycogen) stored in the muscle. For carbs to be transformed into glycogen and be absorbed through the muscle is a lengthy process.

Once consumed, carbs are broken down into smaller sugars (glucose) that are used for immediate activity. The unused glucose is converted into glycogen. Glycogen is then stored in the muscles for later use. Since glycogen is stored in the muscle, it's immediately accessible to the body. The more glycogen you have (to an extent), the more energy you'll have during a race. For a marathon, it's nearly impossible to have enough glycogen for the entire race (which is where the gels come in hand).

When you are running or racing, your body might divert the blood away from your digestive tract. This gives your legs more oxygen, but also inhibits digestion which is why some people get an upset stomach or puke up a gel during a race (and also why you want to start taking gels early and before you need them).

How often should you take Carbohydrates?

Like everything with running and nutrition, each person is different.

For runs over 60 minutes, the average runner should consume 25 grams of carbs about every 45 minutes. Most gels contain 25 grams of carbohydrates, or about 100 calories.

(My PR in the marathon is 3:07, and I’ve found roughly every 45 minutes/5ish miles works for me.)

Since most energy gels come from simple sugars, they will be absorbed into your bloodstream as glucose, and will then be absorbed into the muscles.

Why are Gels the Most Popular?

It’s important to note, while gels are the most common energy source, they aren’t the only energy source. Other sources include gummies, to bars, and drink mixes, there are several ways to consume calories.

Many athletes prefer gels because they are easiest to carry, portable, light, easy to open, squeeze, and consume while running. Since gels are premade, you also don’t have to worry about replicating the same formula like mixing a powder.

How to take a Gel:

Gels are different from other energy sources. Since they are a concentrated carbohydrate and sugar source, you must take them with water. Taking them alone or with an Electrolyte drink can result in stomach issues later down the road.


Without water, gels take longer to consume. If you take a gel with another energy source (like Gatorade), you could take too much simple sugar. Too much simple sugar will likely leave you with an upset stomach or a sugar spike followed by a crash.

Which type of fuel is best?

We all know by now, every brand of anything claims to be the best ever. But there isn’t much scientific proof about the actual best. It’s all personal. The fuel you choose comes down to trial and error and finding out what works for you.

Check out these popular picks

Clif Energy Shot: Inspired by the chews, thicker gel
Gatorade Endurance: known for a thinner consistency
Honey Stinger: Gluten Free
Huma: Double the Electrolytes
Generation UCan: Mixed with water and gentle on your stomach.
Gu: The original “gel” with several different flavors.
Gu Roctane: Designed for longer-lasting energy like ultras
Maurten: Designed for the breaking two project, uses hydrogel.
Skratch Labs: Makes bars, gels, and hydration mixes.
Ultima Replenisher: Mixed with water, no fructose syrup
Untapped: Uses maple syrup

Next week, we will dive into different brands of gels and energy sources. Why take one over the other? What are the benefits of each? Are there disadvantages?

Plus a giveaway including some of the brands.

Discount Codes:

Runners Love Yoga: Use LOLZVACAY for 20% Off (Ann has some cute items out)

Speedo: Use SFHollieS to get 25% off, including the suit I've used for most of the summer.

Finally, thank you to everyone who has shared!

Sharing to one person or 10,000 only takes a second, and it’s the best thing you can do to help the newsletter grow! My goal is to reach 1000 subscribers by the end of the summer. Currently, the newsletter has 940.

Any feedback, good or bad, is always helpful. Is there a specific topic you want to see more about? Don’t be a stranger and let me know! This newsletter came about because people wanted to know more about fueling.

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