The Simple Guide to Hydration and Electrolytes

Staying hydrated is about more than just quenching thirst; it’s about keeping your muscles firing and your power from dropping off a cliff. Here is the simple math you need for your next ride.

You should aim to drink between 500ml and 750ml of fluid every hour you are on the bike, paired with 500mg to 700mg of sodium. If it’s a particularly hot day or you are a "salty sweater" (you see white streaks on your kit), you may need to increase those numbers to 1 liter and 1,000mg of sodium per hour.

Start with a Simple Baseline

Think of your hydration in terms of "standard" cycling bottles. Most small bottles are 500ml, and large ones are 750ml.

• Cool days: One small bottle (500ml) per hour.
• Warm days: One large bottle (750ml) per hour.
• Hot/Humid days: One large bottle plus a few extra gulps (up to 1L) per hour.

Why Electrolytes Matter

Water alone isn't enough for long rides. When you sweat, you lose salt (sodium), which helps your muscles contract and your body absorb the water you're drinking.

If you drink plain water for three hours straight without adding electrolytes, you'll actually dilute the salt in your blood. This can lead to cramping, bloating, or even a dangerous condition called hyponatremia.

Try this: Look for an electrolyte tab or powder that offers at least 500mg of sodium per serving. If your drink mix is low on sodium, you can supplement with salt chews or even a pinch of sea salt in your bottle.

Real-World Examples

To make this easy, let's look at how you'd pack for a two-hour ride:

• The "Standard" Setup: Bring two 750ml bottles. Drop one electrolyte tab in each. Finish the first bottle by the 1-hour mark and the second by the time you get home.
• The "Big Summer" Setup: Bring two 750ml bottles and plan a mid-ride stop to refill. Use a higher-strength electrolyte mix (1,000mg sodium) to account for the heavy sweat.

Why this matters for YOUR training

When you get dehydrated, your blood gets thicker. This makes your heart work harder to pump blood to your legs, which sends your heart rate sky-high even if your power (FTP) stays the same.

By staying on top of your fluids, you keep your heart rate stable and ensure you can finish your intervals as strong as you started them. You'll also recover much faster once you're off the bike because you aren't starting from a "deficit."

Summary

• Drink: 500ml–750ml per hour.
• Salt: 500mg–700mg of sodium per hour.
• Check: If your kit has white salt crust, increase your sodium intake.
• Action: Set a timer on your head unit for every 10–15 minutes to remind you to take a sip.