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How much water should runners drink?

Do you really need to lug a massive jug of water around with you all day?

Everyone has that one friend who never leaves home without their two-litre jug of water, and not surprisingly, this is usually the same friend who’s constantly looking for the nearest bathroom. But is this water-guzzling pal onto something? It’s no secret that drinking water is good (and necessary) for the health of runners and non-runners alike, but exactly how much water do we actually need? This answer will vary for everyone, but use these guidelines to determine if you’re staying hydrated.

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Why is hydration so important?

Staying hydrated is important for runners for a number of reasons. It enhances your body’s ability to regulate temperature and cool itself down efficiently without unnecessarily elevating your heart rate, and improves your ability to recover quickly from a workout or race. Staying hydrated can also help to minimize muscle cramps, enhance your mental function and focus and support your immune system.

In terms of general health, water helps to lubricate joints, protect your organs and tissues, flushes out waste products to lessen the workload for your liver and kidneys, helps make nutrients accessible to the body and carries nutrients and oxygen to the cells.

How do you know if you’re dehydrated?

Signs and symptoms of dehydration include:

  • difficulty or inability to concentrate
  • early fatigue in training sessions
  • feeling like you have to work much harder during training to hit paces that are normally easy
  • difficulty tolerating the heat
  • slow or delayed recovery
  • headaches
  • muscle cramps
  • nausea and vomiting
  • your heart rate is higher than normal during training

According to Trent Stellingwerff, a physiologist with Athletics Canada, athletic performance can be negatively affected by as little as two to four per cent bodyweight loss from sweat. That is the equivalent of about three to five pounds for a 150-lb athlete. This level of dehydration is also enough to raise your risk for injuries like cramps or muscle pulls.

Most people wait until they feel thirsty before they drink water, but according to the Mayo Clinic, thirst could indicate that you’ve already lost one to two per cent of your body’s water content. This level of dehydration is not dangerous to your health, but if you’re a high-performance athlete, it could affect your results in runs and workouts.

Aside from a decrease in body weight, another way for runners to monitor their hydration status is to pay attention to the colour of their urine. A hydrated individual’s urine will be pale yellow, and as you get more dehydrated, your urine will get darker. If your pee is a four or above on the chart below, you are already dehydrated enough to possibly impact performance. Again, it’s worth noting that this chart is directed at high-performance athletes, and being at a four on the chart isn’t dangerous to your health.

Athletics Canada

How much water should you be drinking?

Every individual is different, and your own water needs will vary depending on the temperature and how much you’re training that day. This is why it’s important to monitor your hydration status and adjust accordingly, especially in hot or humid conditions. Here are a few guidelines to help you ensure you’re drinking enough water:

  •  Carry a water bottle with you, or keep a glass of water on your desk to help you drink more water during the day.
  • Aim to drink two cups of water with meals.
  • Choose fruits and veggies that have a high water content to have with snacks and meals, like oranges, berries, melons and pineapple, cucumber, bell peppers and zucchini.
  • Some of your water can be consumed in the form of another type of beverage, like 100 per cent fruit juice, herbal tea, milk or milk alternatives.
  • Include soup as a side with lunch or dinner.
  • If you’re running for more than 60 to 90 minutes on a hot day, a sports drink may help replenish fluids and electrolytes lost through sweat.

Keep in mind that it is possible to overhydrate, which will flush electrolytes out of your body and negatively affect your health and performance. Drinking too much water could also lead to hyponatremia, which is when the sodium concentration in your blood is abnormally low. When this happens, the cells of your body begin to swell, which can be life-threatening. If your urine is clear, or if you’re waking during the night to pee more than twice, you are likely overhydrated.

The bottom line

As long as your pee is pale yellow in colour, you’re likely hydrated enough to maintain good overall health status. In this respect, drinking water when you feel thirsty is likely adequate for the average person. If you’re a competitive runner with a large training load, avoiding dehydration can help you maximize performance, but recreational runners may not need to be quite as regimented with their water consumption. Finally, if you’re someone who does prefer to drink large amounts of water throughout the day, monitor your pee colour, and if it’s extremely pale or completely clear, you may want to drink a little less.

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