Step 1: Start Training Hydrated

A lot of hydration issues begin before the session starts.

Practical guideline:

Drink ~5–10 mL per kg bodyweight in the 2–4 hours before training

Example for a 70 kg athlete:

• 350–700 mL

This helps:

• top up fluids,

• start well hydrated,

• avoid early dehydration.

These pre-exercise ranges are consistent with ACSM guidance and recent personalized hydration research.

Good options are:

• water

• water + electrolytes if hot

• light sports drink

Step 2: During Training — Drink to Match Conditions

There is no perfect number for everyone.

Hydration needs depend on:

• sweat rate

• body size

• heat

• humidity

• intensity

• duration

General guideline during exercise:

~0.4–0.8 L per hour

This works well for many athletes in endurance sessions.

Practical examples:

Cool conditions / easy session:

• 300–500 mL/hour

Moderate conditions:

• 500–750 mL/hour

Hot / high sweat:

• 750–1000+ mL/hour (if tolerated)

Important: don’t force huge amounts just because a watch tells you to.

Drink steadily:

• small sips,

• every 10–20 minutes.

Step 3: For Longer Sessions, Sodium Matters

For sessions:

• over ~90 minutes,

• in heat,

• heavy sweaters,

• salty sweaters,

…plain water alone is often not enough.

Sodium helps to:

• retain fluid,

• stimulate thirst,

• support muscle and nerve function,

• reduce risk of hyponatremia.

Practical sodium target is~300–600 mg sodium per hour

This is a widely used range in endurance sports guidance.

Heavy sweaters may need more some athletes lose:

• 500–700+ mg sodium/hour,

• sometimes far more.

Easy ways to get sodium:

• sports drink

• electrolyte tabs

• gels with sodium

• salty foods (on long rides)

Step 4: Match Hydration to Session Type

Short easy session (<60 min)

Usually:

• normal hydration before is enough

• drink to thirst if needed

Moderate session (60–90 min)

Usually:

• water may be enough

• more if hot

Long session (90+ min)

Best:

• structured fluid plan

• carbs + sodium

Race / heat / long endurance

You should:

• test your hydration strategy in training

• know what your stomach tolerates

Never try new products on race day.

Step 5: Learn Your Sweat Rate (Most Useful Tool)

This is one of the best ways to personalize hydration.

Simple test

Weigh yourself:

• before session

• after session

And track:

• fluid consumed

Example: 1 kg bodyweight lost after session = ~1 L sweat loss

This helps you:

• estimate hourly losses

• avoid under / overdrinking

Recent research strongly supports individualized hydration over generic rules.

Step 6: Rehydrate Properly After Training

If you finished:

• very sweaty,

• dehydrated,

• in heat,

…replace losses.

Practical example:

For every 1 kg body mass lost → drink ~1.25–1.5 L over next few hours

Include:

• sodium,

• normal meals,

• fluids.

This helps restore fluid balance more effectively than water alone.