Hydration & Electrolyte Calculator
Your Daily Protocol
Daily Cost Comparison
(That's £0.00 kept in your pocket every single day)
The Science of Sweat
One size does not fit all. The "8 glasses of water a day" rule is outdated myth, especially for endurance athletes. The Invigorate Precision Hydration Calculator uses metabolic science to estimate your specific fluid and electrolyte losses based on three critical variables: Intensity, Duration, and Environmental Conditions.
Dehydration of just 2% of your body weight can reduce aerobic performance by up to 20%. Conversely, over-drinking plain water can lead to Hyponatremia (low blood sodium). This tool finds your sweet spot.
Why Sodium Matters More Than Water
When you sweat, you don't just lose water; you lose critical electrolytes, primarily Sodium. Sodium is the mechanism that allows your body to hold onto fluid. Without it, the water you drink passes straight through you, doing nothing to rehydrate your cells or blood plasma volume.
- Prevent Cramping: Neuromuscular fatigue combined with electrolyte imbalance is a leading cause of muscle cramps.
- Maintain Blood Volume: Proper sodium intake keeps your blood volume high, reducing the strain on your heart (Cardiac Drift).
- Mental Clarity: Electrolytes are essential for nerve transmission. Staying hydrated keeps your focus sharp at mile 20.
Frequently Asked Questions
When should I drink electrolytes?
For workouts under 60 minutes, water is typically sufficient. However, for sessions longer than 60-90 minutes, or high-intensity intervals in heat, you should begin sipping an electrolyte mix 30 minutes prior to starting and continue every 15-20 minutes during activity.
How do I calculate my Sweat Rate?
This calculator provides a scientific estimate. for 100% precision, try a simple home test: Weigh yourself naked before a 1-hour run (no drinking during). Weigh yourself after. The weight lost (in lbs/kg) is roughly your hourly fluid loss.
How does this fit into my training plan?
Hydration strategy is just one pillar of performance. To see how these hydration numbers fit into a full season of training, generate a free custom schedule with our Marathon Training Plan Generator.
Why you need electrolytes
Electrolytes like sodium, potassium, calcium, and magnesium are the electrical sparks that keep your body running. They regulate fluid balance, muscle contractions, and brain function. Without them, water alone can't fully hydrate you, leading to fatigue and cramping. Dive deeper into the science below:
Fuel your body the right way.
Invigorate delivers a precise blend of sodium, potassium, magnesium, and calcium — the essential electrolytes your body needs for optimal hydration and performance.
Zero sugar, zero calories
Flavoured with natural fruit
No fillers or harmful sweeteners
Designed for clean, effective hydration — every day.
One pouch = 90 servings of premium hydration.
That’s just 25p per serving — compared to an average of £1.24 for competitors sachets.
At two servings a day Invigorate can save you over £700 per year compared to single-serve sachets. Think of the extra running shoes or bike gear!
Bundle deal - get 15% off when you buy two pouches OR shop our ‘Ultimate Endurance Bundle’ which includes an Invigorate Pro Bottle.
One serving contains:
Sodium 500mg
Potassium 250mg
Calcium 100mg
Magnesium 50mg
(See here for full nutritional information)