Water makes up more than two-thirds of the human body, and when you become dehydrated—which can be very easy to do during intense physical activities like hiking, cycling and running—your body and brain suffer serious consequences.
To protect yourself from the harmful effects of dehydration, it's important to be intentional about hydration on and off the trail. Not convinced? Take a look at five ways your body could be impacted if you neglect to properly hydrate.
Your Brain Doesn't Work as Well
When you're in the middle of a high-intensity outdoor activity is the last time you want a foggy mindset, yet dehydration's most instant side effects are seen on the brain. One study found that even mild dehydration can lead to difficulty performing simple mental tasks. Specifically, women were found to have difficulty concentrating while men were less likely to be vigilant and also struggled with memory recall; either way, those are side effects you don't want to deal with on the trail.
You Could Intensify Anxiety or Depression
The brain is hardwired to give mental warning signs when something is physically wrong. When they're parched, your muscles and organs don't perform as well, and that physical stress on your body is manifested as mental stress and even anxiety. It's the body's way of telling you to pay attention and hydrate properly.
Those symptoms are intensified as you become more dehydrated. In fact, being severely dehydrated decreases serotonin, which could lead to serious mental health problems like depression. Staying hydrated is the simplest way to avoid the mental health risks associated with a thirsty brain.
Your Skin Suffers
Dehydration can cause your skin to look grey, dull and lifeless in the short term. In the long term, your skin could lose elasticity, leading to wrinkles, sagging skin and premature aging. Defend your dermis from these side effects and keep your skin bouncy and fresh by staying hydrated before, during and after intense physical activity.
You're More Susceptible to Illness
Water is the body's primary way of delivering oxygen to your cells and flushing out toxins. Without it, you can potentially leave your body at risk of hoarding harmful toxins, bacteria, and viruses. More seriously, one study even linked dehydration with cancer formation. Be sure to flush your body with plenty of water to help ward off unwanted disease.
Major Organs Could Fail
If dehydration becomes severe and repetitive, you could put important body systems at risk—specifically your urinary tract and kidneys. On the manageable side, you might have to deal with a urinary tract infection. But on the more painful end of that spectrum lie kidney stones and potential kidney failure.
While these are just five side effects of dehydration, other short-term effects can greatly affect your ability to run, cycle or hike in the moment; dry or blurred vision, muscle cramps, and even a fever can all be prevented by simple hydration.
The easiest way to be intentional about your on-the-trail water intake is a hydration pack. This simple solution is non-invasive, and since you don't have to stop to pull a bottle out of a backpack, you can drink more often. Best of all, they hold up to two liters, meaning you can drink more water mid-activity, keeping you hydrated in the short-term and protecting you from long-term conditions down the road.
Ok, So How Much Water Do I Need?
Your body wants to regulate its temperature at a comfortable 98.6 degrees. If you overheat, you sweat — losing about 80 ounces (2.3 liters) per day just from a normal metabolic function. However, some factors can increase this rate.
Level of Physical Activity
It makes sense that the harder your metabolism works, the more you perspire. But you might be surprised to know that during intense exercise in the heat, you lose a shocking 90 ounces (2 to 3 liters) of water per hour. During endurance activities, it’s slightly less at 65 ounces (1.5 to 2 liters) per hour.
Humidity and Heat
High temperatures, humidity and even warm clothing can increase water loss. For any activity, sweating doubles if it’s humid or above 70 degrees outside. For example, runners will lose 42 ounces (1.2 liters) per hour on a cool day but 84 ounces (2.4 liters) on a hot or humid day.
How Often Should I Replenish?
It’s nearly impossible to completely replenish all the water you lose during an activity — even Olympic athletes don’t. But, it’s recommended that your intake should be at least 18 ounces (500ml) per hour at regular intervals. Why regular intervals? Because hyper-hydration (i.e., chugging 500ml of water at once) can cause bloating, nausea and even vomiting. Also, it can suppress thirst — causing further dehydration.
If you want to optimize your performance and avoid negative side effects, you need a sip, or ounce, of water every 3 minutes (double that for hot or intense activities). But that’s a lot of stopping and tilting water bottles, which is why a hydration system can be a fantastic solution.
The system lets you sip away to your heart’s content every few minutes without interrupting your activity. You stay hydrated, avoid all the bloaty side effects, and maintain your performance — saving some serious time off your run, cycle or hike.