A town near my home has a (moderately hilly) 50-mile bike ride in the summer every year. Last year on the ride, someone told me I should have been drinking significantly more water the day before to "pre-hydrate", as my body was expending more water due to exertion and heat than I could recover by drinking.

Is this true? Should I drink more water the day before a tough ride?

(For reference: this is the route)

  • 2
    Hydration is pretty much never a bad thing. Unless you are hydrating on alcohol.
    – paparazzo
    Jun 17, 2015 at 20:41
  • 1
    True hydration is a balance of fluids with electrolytes and nutrients. Just drinking more water is not always the answer. Jun 17, 2015 at 21:09
  • @Chris - In this context the intake need not be so fast the body does not have the ability to balance the electrolytes within the digestive system.
    – mattnz
    Jun 17, 2015 at 21:17

2 Answers 2


"More" - more than what - if you are already an '8 litre a day' person, no it will not help. If you are like me (too much coffee, drink when I am thirsty), an extra couple of litres spread evenly over the day will be a good thing.

Be careful not to over hydrate as it will change the balance of electrolytes in you system and could lead to problems such as cramping. A litre extra over a day won't be an issue, but more than that, use a proper electrolyte drink (Not the lolly water sold at supermarkets as 'sports' drinks - if it tastes good, its not electrolyte).

Watch out for too much water causing you get up for the toilet all night and miss out much needed sleep.

In summary - a little more than usual is probably good, too much more is not so good.

  • Your kidneys regulate the amount of excess water in your body, and will quickly create urine to eliminate any excess buildup from drinking water. Even 3-4 cups of coffee a day doesn't act as a diuretic. An extra 2 liters would be an excessive amount, as your body only needs about 2 liters of water a say (some of which is provided by the food you eat). mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/… So based upon the evidence, I'd say drinking 2 liters MORE water a day than normal even if you drink coffee is bad advice. Jun 19, 2015 at 3:50


Before any ride you should be fully fueled - eaten appropriate food, enough of it, and drunk enough to be fully hydrated. See the answer by mattnz regarding electrolytes.

Just before you start have a good drink, then drink a little and often on the ride, before you feel dry or thirsty. After the ride make sure you drink plenty, and eat a balanced meal.

But perhaps you aren't normally properly hydrated (like most people), and this caused a problem last year. If that's the case, then it's not just the day before - it should be every day! Kidney damage due to lack of hydration is common.

Whether a given ride is tough or not depends on two things

  • your cycling fitness at the time

  • the weather at the time.

The MapMyRide page you link to is a bit deceptive, suggesting that the climbs are around 2%. On Strava I see that there are multiple short climbs of 6-7-8%, some of 10-12%, and a few short pitches up to 16%. I see that the longest climb is in the last 5km. Most people would agree that those steeper gradients can be tough, so I would focus on some climbing practice, rather than worry about water. Manage the water, build your strength.

In summer the climate in Perry is very mild (82°F, 28°C), so unless it's unusually hot or windy, it will not be an issue. Just carry two full bottles of water from the start. You didn't ask about food, but it looks like a one-banana ride to me. Eat half after an hour, the other half an hour later.


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