Electrolytes for Athletes: Complete Guide

What Are Electrolytes?

Electrolytes are minerals that carry an electrical charge when dissolved in water. They're essential for:

• Muscle contraction
• Nerve function
• Fluid balance
• Blood pressure regulation

Main Electrolytes

Sodium (Na+)

Functions:

• Fluid balance
• Nerve impulse transmission
• Muscle contraction

Loss in sweat: 200-2000mg/L (most lost electrolyte)

Deficiency symptoms:

• Headache
• Nausea
• Muscle cramps
• Confusion
• Fatigue

Potassium (K+)

Functions:

• Heart rhythm
• Muscle contraction
• Nervous system

Loss in sweat: 100-400mg/L

Deficiency symptoms:

• Muscle weakness
• Cramps
• Fatigue
• Heart rhythm issues

Magnesium (Mg2+)

Functions:

• Muscle relaxation
• Energy production
• Protein synthesis

Loss in sweat: 10-50mg/L

Deficiency symptoms:

• Muscle cramps
• Fatigue
• Sleep issues
• Anxiety

Calcium (Ca2+)

Functions:

• Bone health
• Muscle contraction
• Blood clotting

Loss in sweat: 20-60mg/L

When Is Electrolyte Supplementation Needed?

Definitely needed:

• Training over 60 minutes at intense level
• Hot and humid weather (more sweating)
• Heavy sweater (some sweat more)
• Two or more workouts per day
• Long endurance events (marathon, triathlon)

Probably not needed:

• Training under 60 minutes at moderate intensity
• Cool weather (less sweating)
• Light exercise (walking, yoga)

Electrolyte Sources

Sports Drinks

Advantages:

• Convenient
• Fast absorption
• Also contains carbohydrates

Disadvantages:

• Often too much sugar
• Can be expensive
• Some contain artificial additives

Examples: Gatorade, Powerade, Isostar

Electrolyte Tablets/Powders

Advantages:

• Control sugar amount
• Cheaper long-term
• Precise dosing

Disadvantages:

• Needs water to mix
• Less convenient

Examples: Nuun, SiS, Precision Hydration

Natural Sources

Dosing During Training

Sodium

Practical Guide

BEFORE training (2-3h before):

• 500ml water + light salty meal
• Or electrolyte drink

DURING training (over 60 min):

• 500-750ml electrolyte drink/hour
• Or water + electrolyte tablets

AFTER training:

• Electrolyte drink or salty food
• Drink until urine is light colored

Hyponatremia - Too Much Water

What is it? Too low sodium levels in blood from drinking lots of water without electrolytes.

Symptoms:

• Nausea
• Headache
• Confusion
• Seizures
• In severe cases - loss of consciousness

Prevention:

• Don't drink too much water
• Add electrolytes during long workouts
• Drink to thirst, not on schedule

How to Know Your Sweat Rate?

Simple Test:

1. Weigh yourself before workout (without clothes)
2. Train for 1 hour
3. Weigh again after workout (dry off sweat)
4. Calculate: Before - after + fluid drunk = sweat rate

Example:

• Before: 80kg
• After: 79.2kg
• Drunk: 500ml (0.5kg)
• Sweat rate: 80 - 79.2 + 0.5 = 1.3L/hour

Categories:

• Low: <0.5L/hour
• Medium: 0.5-1L/hour
• High: 1-1.5L/hour
• Very high: >1.5L/hour

Our Recommendation

For Short Workouts (<60 min)

• Water is sufficient
• No electrolytes needed
• Eat balanced food before and after

For Longer Workouts (60-90 min)

• Electrolyte drink or water + tablets
• 300-600mg sodium per hour
• Drink to thirst

For Long Workouts (90+ min)

• Electrolyte drink definitely
• 500-1000mg sodium per hour
• Add carbohydrates for energy
• Practice hydration strategy

In Hot Climate

• Add 30-50% more electrolytes
• Start hydrating earlier
• Drink more regularly

Summary

Electrolytes are critical for athletic performance, especially during longer and more intense workouts.

Key points:

• Sodium is the main electrolyte lost in sweat
• Training over 60 minutes needs electrolyte supplementation
• Drink to thirst, not excessively
• Need more in hot weather
• Know your sweat rate

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Browse our electrolyte selection at MaxFit.ee →

See also:

• Electrolyte Powder vs Tablets: Comparison for Athletes
• Hydration Guide for Athletes: Water, Electrolytes, and Performance
• Potassium: The Essential Electrolyte for Muscles and Heart

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Read more: Electrolytes: A Science-Based Guide