Water is truly the “fluid of life”, critical for the optimal function of all systems in your body. You are made up of over 3 trillion cells, all of which are constantly “talking” to one another to keep your body and brain running on all cylinders. Hydration is crucial to this communication; if your water intake from fluids and foods doesn’t meet your body’s demands, your health and performance will suffer.
How Do You Know If You’re Not Properly Hydrated?
Common symptoms of dehydration include a dry or sticky mouth (especially first thing in the morning), constipation (as your body draws from resources in the gut to make up for sub-optimal hydration), headaches, dry skin, decreased urine output, thirst and light-headedness.
There are a number of factors that can contribute to sub-optimal hydration, however the most common causes include intense exercise, training in hot weather, excessive caffeine or alcohol intake, diarrhea, fever and excessive sweating.  If symptoms of dehydration become severe, they require immediate medical attention. Extreme thirst, low blood pressure, rapid heart rate, fever, or increased breath rate are all red flags and are most commonly experienced during endurance competitions, in older adults, or when training in hot weather or at high altitudes.
Hydration & Exercise
While thirst may be a reliable indicator for some people to maintain the right level of hydration, the more active you are, the less reliable it becomes. Incredibly, a mere 2% drop in hydration can lead to an 8-10% decrease in your performance.  If you wait until you “feel thirsty”, you’ve waited too long. Studies show that by the time you feel thirsty, you’re already dehydrated.  If maintaining high productivity or achieving a new personal best is your primary goal then it’s crucial to ensure you are getting sufficient water to meet your training demands.
However, the reality is that the optimal intake of water varies significantly from one individual to the next. Depending on your age, sex, body type, level of health and activity, your ideal water intake will vary. The standard general guideline is to consume 8 glasses of water daily, divided throughout the day. While this is a good tip for most people, a Paleo diet is rich in fruits and vegetables which provide you with added hydration, so you may not need the full 8 cups.
How can you tell if you’re getting enough fluids in through water and food? Drink enough water to keep the color of your urine light yellow to clear. The darker your urine becomes, generally the more dehydrated you are (however, if you’re taking B-vitamins, they make your urine bright yellow, so this tip won’t apply).
Are Sports Drinks the Best Option for Refueling During Exercise?
For most people, water is sufficient for rehydration during exercise. However, the more intensely you train or the longer you train (i.e. greater than 90 minutes), it’s important to add electrolytes to your water. If you’re a heavy sweater or train in warm climates, you might even need salt tablets to maintain sodium levels.