The Importance of Hydration for Exercise Performance

You can have the perfect workout program, dial in your nutrition, and get 8 hours of sleep every night. But if you're not properly hydrated, you're leaving performance on the table.

Water makes up about 60% of your body weight. Your muscles alone are roughly 75% water. It's involved in virtually every bodily function—especially the ones that matter for fitness.

Why Hydration Matters for Exercise

Here's what happens when you're properly hydrated:

• Temperature regulation – Your body can cool itself efficiently through sweat
• Nutrient transport – Proteins, carbs, and vitamins get delivered to muscles
• Joint lubrication – Reduced risk of injury and joint pain
• Waste removal – Toxins and metabolic waste are flushed out
• Energy production – Proper cellular function requires water

Studies show that even 2% dehydration can decrease performance by up to 25%. That means if you normally lift 200 lbs, dehydration could make it feel like 250 lbs.

Signs You're Dehydrated

Your body gives you signals when it needs water. Pay attention to:

• Thirst – The obvious one (though if you're thirsty, you're already mildly dehydrated)
• Dark urine – Aim for pale yellow, not dark amber
• Fatigue – Feeling tired during workouts that are normally manageable
• Headaches – Common symptom of dehydration
• Dizziness – Especially when standing up quickly
• Decreased performance – Struggling with weights you normally handle
• Muscle cramps – Often related to dehydration and electrolyte imbalance

How Much Water Do You Actually Need?

The "8 glasses a day" rule is overly simplistic. Your actual needs depend on:

• Body weight
• Activity level
• Climate
• Sweat rate
• Diet (some foods contain water)

A Better Formula

A practical starting point:

For example, a 180 lb (82 kg) person should drink between 90-180 oz (2.4-3.3 L) daily. Active individuals should aim for the higher end.

Add extra for exercise: Drink an additional 16-24 oz (500-700ml) for every hour of exercise.

When to Drink: Before, During, and After

Before Exercise

• Drink 16-20 oz (500-600ml) 2-3 hours before exercise
• Drink another 8 oz (250ml) 20-30 minutes before

During Exercise

• Drink 7-10 oz (200-300ml) every 10-20 minutes
• For workouts over 60 minutes, consider adding electrolytes

After Exercise

• Drink 16-24 oz (500-700ml) for every pound lost during exercise
• Don't know how much you lost? Weigh yourself before and after

Electrolytes: The Other Half of the Equation

Water alone isn't enough. When you sweat, you lose electrolytes—minerals that help regulate fluid balance, muscle function, and nerve signaling.

Key electrolytes for exercise:

• Sodium – The most important for exercise; lost in highest amounts through sweat
• Potassium – Helps with muscle contractions
• Magnesium – Prevents muscle cramps
• Calcium – Important for muscle function

For workouts under 60 minutes, water is usually sufficient. For longer or more intense sessions, consider:

• Electrolyte drinks or tablets
• Coconut water (natural source of potassium)
• A pinch of salt in your water

Track Your Hydration

Like everything else in fitness, what gets measured gets managed. Tracking your water intake helps you:

• Build the habit of drinking enough
• Identify patterns (maybe you drink less on busy days)
• Correlate hydration with performance

The Bottom Line

Hydration isn't sexy, but it's fundamental. Before you buy another supplement or try another program, make sure you're drinking enough water.

Start simple:

1. Drink a glass of water when you wake up
2. Carry a water bottle throughout the day
3. Drink before, during, and after workouts
4. Track your intake to build the habit

Your performance—and your body—will thank you.