Homemade Energy Gels for Endurance Athletes: A Science-Backed, Low-Cost Fueling Strategy

As a full-time student training for a marathon, commercial gels are convenient, but they’re essentially carbohydrate, sodium, water, and sometimes a gelling agent. With a basic understanding of carbohydrate delivery and osmotic tolerance, you can formulate your own for a fraction of the cost, tailored to your physiology, without compromising on performance.

So, over the past few weeks I’ve been experimenting with a homemade energy gel recipe to fuel my training while keeping cost low. After spending a while sourcing the ingredients and trialing out different ratios, I think I’ve come close to perfecting it for my own training. In hopes of educating, entertaining, and hopefully empowering you, I’ve shared the recipe here.

This recipe yields 3 servings of 100 mL gels (~60 g carbohydrate per 100 mL gel) using a 1:0.8 glucose-to-fructose ratio to optimize carbohydrate absorption at >60g/hour.

To learn more about the science and story behind this gel, a cost analysis, considerations for trying them, advantages and disadvantages, along with a demonstration on how to make them, check out the video below.


What Does This Actually Cost?

With how I procured the ingredients, this recipes sits at approximately:

$1.18 per gel for 60g of carbohydrate

For comparison, a single serving of a high-level gel brand typically costs around:

$5.50 per gel for 25g of carbohydrate

That’s more than 10x the cost for the same amount of carbohydrate.

If you’re fueling:

  • 2-4 gels per long run

  • 1–2 long runs per week

  • A 16-week marathon block

That difference can easily exceed $500–1000 over a training cycle. Even more if you run these distances year-round.

For student-athletes, high-mileage year-round runners, or anyone balancing performance and finances, that matters.


Ingredients (Per 300 mL Batch – 3 Servings)

  • Dextrose (glucose): 100 g → main energy source

  • Fructose: 80 g → secondary energy source

  • Sodium alginate: ~6 g (≈2-3 tsp) → gelling agent

  • Salt: ½ tsp → Replenish sweat losses and improve uptake

  • Calcium lactate gluconate (optional): ~0–0.2 g (a small pinch) → solidify the gel

  • Emulsified flavoring (optional): 1–2 mL (a drop or two is sufficient) → make it taste good (super important!)

  • Water: Add to total volume of 300 mL → alter texture and concentration

  • 100 mL food safe silicon tubes → delivery mechanism


Method

1. Hydrate the Alginate

Measure 150–200 mL of water. Add the alginate and water to a blender and blend to prevent clumping. Alternatively, add slowly while whisking. Let sit for 10–15 minutes to fully hydrate.

2. Dissolve the Carbohydrates

Warm the mixture gently to 40–50°C (warm, not too hot).
Add the following:

  • 100 g dextrose

  • 80 g fructose

  • ½ tsp salt

Stir until completely dissolved.

3. Add Flavor (Optional)

Add a small amount (1–2 mL) of concentrated emulsified flavoring. A little goes a long way.

4. Adjust Texture (Optional)

Dissolve 0–0.2 g calcium lactate gluconate in ~10-20 mL water. Add gradually while stirring gently to slightly thicken the gel. More calcium = a more solid-textured gel.

5. Adjust Final Volume

Add water as needed to bring total volume to 300 mL.

6. Portion & Store

Divide into three 100 mL soft flasks or reusable gel containers. Let rest 30–60 minutes to stabilize texture. Refrigerate until use.


Nutritional Info (Approx. Per Gel)

Calories: 240 kcal

Carbohydrate: 60 g

  • ~33 g glucose

  • ~27 g fructose

Protein: 0 g

Fat: 0 g

Sodium: ~430–450 mg

Estimated Osmolarity: ~3670 mOsm/kg

Carbohydrate Concentration: ~60%

I hope this is helpful, have fun training!

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