How Long Does It Take to Rehydrate?

Do you find yourself tired often, or feel weaker when you wake up or exercise? Does stuffing yourself with pizza and other salty foods leave you ready for a nap? If so, chances are that you need to rehydrate.

Nobody likes to wake up with a headache after a long night out. Sure, you probably told yourself you would drink water before, during, and after. Unfortunately, that doesn’t seem to happen. Drinking waterfalls to the back of a lot of people’s minds despite being one of the top ways to feel your best. So now that you’re feeling the effects and need to rehydrate, how long do you have to deal with a headache? The answer is: it varies.

Why Is Water So Important?

If I told you that 60% of your body was evaporating and being constantly depleted, what would you say? What if all you had to do to fix it was to drink water every so often? As dramatic as that makes it sound, that is practically how water works in your body.

Water makes up about 60% of your body weight (and more if you’re bloated.) and is used up constantly. You lose water through breathing, sweating, using the bathroom, and more. Your body will also use the water it has available in order to perform maintenance on your body, including:

  • Regulating temperature
  • Lubricating joints
  • Creating tissue
  • Allowing cells to function
  • Aiding digestion
  • Transporting nutrients and waste

As you can tell, these are some pretty important bodily functions that are powered by water. With how cheap, readily available, and beneficial water is to most people, keeping yourself hydrated is a no-brainer.

Are You Dehydrated?

Many people are suffering from slight to mild dehydration and don’t even know it. Dehydration shows up in a variety of ways and is relatively easy to diagnose. What many attributes to hunger, a lack of sleep or stress else could often be solved with a few glasses of water. So, put down the pill bottles and check to see if you are dehydrated first.

Common symptoms of dehydration are:
  • Increased thirst
  • Tiredness
  • Dry mouth
  • Darker urine
  • A headache
  • Dry skin
If you allow yourself to become severely dehydrated, you risk experiencing more dangerous symptoms like:
  • Increased heart rate
  • Drastic blood pressure changes
  • Fever
  • Confusion
  • Seizures and shock

Now that you know the dangers of neglecting your hydration, it’s time to figure out how much water you need to stay fully hydrated.

How Much Water Do You Need?

The specific amount of water you need to be alert and healthy varies on a variety of factors. Many will simply tell you that if you are thirsty, you need to drink water. Others will say there are a proven 64 ounces a day minimum – 8 glasses of 8 ounces. The reality, however, depends on your body, lifestyle, and environment more than any rules or standards set by scientists.

As we stated previously, you lose water through sweating. This can be during exercise, or simply during your sleep or sitting down. A useful indicator of how much water you will need to replace is to monitor your body temperature and sweating. If you are warm and sweating often, you will need more water to regulate your body temperature and replace the water lost through perspiration. Additionally, if you exercise regularly you are more likely to raise your body heat and sweat extensively, making the need to replace the fluids even greater. Otherwise, you can risk experiencing fatigue, dizziness, and more.

Your overall health also helps to determine how much water you need to rehydrate yourself. Aside from sweat, your body also needs water for normal bodily functions like urination and other digestive functions. If you are sick and find yourself in the bathroom often, you will likely need to increase your water intake to keep up with the loss of fluids. Additionally, those with high salt diets are more likely to be dehydrated, as excess sodium pulls water from your cells, dehydrating them – and you.

How to Rehydrate Yourself Quickly

The best way for you to rehydrate yourself is to not allow yourself to become dehydrated at all. You may not be able to drink enough water during the night, but consciously drinking water throughout the day should do more than enough to keep you hydrated. Be sure to keep an eye on your urine (clearer is better, but not too clear) and how thirsty you are as indicators of how much you need to drink.

If you plan to exercise or be without free access to water for an extended period of time, you can hydrate yourself beforehand to make sure you have enough water to get you through the workout. Studies have shown that about 600ml of water an hour before the workout is enough to keep you properly hydrated through a workout. You can also use sports drinks that are rich in electrolytes to hydrate you more quickly during or after the exercise, as they contain minerals and sodium that is lost from excessive sweating.

If you find yourself only mildly dehydrated while being relatively inactive, you likely won’t have to do much outside of drinking some water or a sports drink. You’re likely to be mildly dehydrated after a workout or after waking up, but mild dehydration can progress to more extreme cases if you don’t get hydrated, so make sure you get some water in you ASAP. You are likely able to fully hydrate from a state of mild dehydration in about 45 minutes with 600ml of water, with sports drinks likely taking slightly less time and fewer liquids.

If you experience extreme dehydration, it can be a medical emergency. At that point, getting yourself hydrated right away is the goal. If you believe it is past simply being able to drink water, and are experiencing the symptoms listed above, you can visit an emergency room. There they will be able to hydrate you within minutes through a saline drip in an IV. This is the fastest way to hydrate, but should not be relied upon except in emergency cases.


Overall, the amount of water required and how long it will take to rehydrate yourself varies based on your health, environment, diet, and the drink you choose. You can’t go wrong with the water, and because it takes only about 45 minutes to hydrate yourself, it is an effective way to maintain your hydration throughout the day.

If you plan to sweat excessively, are sick, or plan to drink, a sports drink can help you replace the minerals lost at the expense of some calories and sugar, and will taste better than plain water. As a general rule, you should drink water as often as you can, especially when thirsty.

Leave a Comment

Your email address will not be published. Required fields are marked *