Running can be expensive, from Gels to bibs and race shoes. So I started making my own electrolyte mix to help save some money. There are some area’s in running that you just can’t reduce costs on, a bib is $100-300 no matter what. But why spend $1 per drink when it can cost you $0.10! LMNT Alternative.

I won’t bury the lead, DIY Electrolyte Mix is right at the top. Enjoy!

Recipe

Makes about 100 servings:

• 25g MgS04 (magnesium sulfate/epsom salt)
• 8g calcium carbonate
• 80g Salt
• 367g sodium citrate (hydrated)
• lime juice for flavour.

Per 1/2 teaspoon (roughly 3g):
1000mg sodium
200mg potassium
50 mg calcium
50 mg magnesium

You’ll need a food scale. Get an old container or ziploc bag. Make sure to mix prior to scooping into your drink just incase anything has settled to the bottom.

LMNT is a very popular Electrolyte supplement. For $39 per month you get 1 box of 30 packs. $1.30/ea.

Per 1 sachet:
1000mg sodium
200mg potassium
60 mg magnesium

Note: Use food-grade ingredients and consult a professional if you have medical conditions or concerns.

Cost

• MgS04 (magnesium sulfate/epsom salt) – $18 for 5 lbs bag
• calcium carbonate – $19 for 500g
• Salt – $14 for 5 lbs
• sodium citrate (hydrated) – $24 for 1 kg

Breakdown

Ingredient	Amount	Cost per g	Batch Cost
MgSO₄	25 g	$0.0079	$0.20
Calcium carbonate	8 g	$0.0380	$0.30
Salt	80 g	$0.00617	$0.49
Sodium citrate	367 g	$0.0240	$8.81

Which works out to $9.80 per 100 servings

Why Runners Need Electrolytes

Runners lose significant amounts of electrolytes through sweat, especially during long runs, hard workouts, and training in warm or humid conditions. While drinking water is important, water alone does not replace the minerals lost during exercise and can sometimes dilute blood sodium levels if consumed in large amounts without electrolytes.

Sodium is the most important electrolyte for runners. It plays a central role in maintaining fluid balance, supporting blood volume, and regulating cardiovascular function. When sodium levels drop too low, runners may experience early fatigue, reduced performance, dizziness, or cramping—even if they are drinking enough water.

Electrolytes also support muscle contraction and nerve signaling. Potassium and magnesium, while lost in smaller quantities than sodium, help ensure muscles fire correctly and remain coordinated during prolonged or intense efforts. Inadequate electrolyte intake can increase the risk of muscle dysfunction and neuromuscular fatigue.

For endurance athletes, hydration and fueling are related but distinct needs. Electrolytes help the body retain and use fluid effectively, while carbohydrates provide energy. Separating the two allows runners to adjust intake based on workout duration, intensity, and individual sweat rate rather than relying on one fixed sports drink formula.

In practical terms, electrolytes help runners stay hydrated, maintain performance, and recover more consistently, particularly during long training sessions, high-volume weeks, and races where sweat losses are high.

How Much do you need?

Sodium: The Primary Driver

Sodium is lost in the greatest quantity during running. Most runners lose 500–2,000 mg of sodium per hour, depending on sweat rate, heat, and individual sweat composition. Research consistently shows that replacing 500–1,000 mg of sodium per hour during long runs and races helps maintain blood volume, improves fluid absorption, and reduces performance decline.

Potassium: Supportive, Not Primary

Potassium losses during exercise are much smaller than sodium. Most runners only need 100–300 mg per hour during long efforts to support muscle contraction and nerve signaling. Higher amounts do not improve performance and may cause gastrointestinal issues.

Magnesium: Neuromuscular Support

Magnesium losses in sweat are low, but endurance athletes often have marginal intake. Including 25–100 mg per hour supports muscle relaxation, energy metabolism, and neuromuscular stability without risking stomach upset.

Calcium: Long-Duration and Durability Support

Calcium is lost in sweat at similar levels to magnesium and plays a role in muscle contraction and nerve transmission. While not critical for short workouts, 50–200 mg per hour can support muscle function and long-term durability during high-volume training and marathon racing.

Practical Guideline

For most runners during long runs, workouts over 90 minutes, or races:

• Sodium: 500–1,000 mg per hour
• Potassium: 100–300 mg per hour
• Magnesium: 25–100 mg per hour
• Calcium: 50–200 mg per hour
  

Exact needs vary by sweat rate, climate, and individual physiology, but these ranges cover the majority of endurance runners.

Disclaimer: I’m not a medical expert, please consult your doctor