Dehydration Myths
Hydration is a problem for everyone – office workers deal with dry environments from conditioned air and need to increase fluid intake to compensate. Athletes bodies use it more quickly and it is easier to get into a very dangerous place. As fall marathon season starts it is important to separate fact from myth to keep hydrated and safe.
Through the years there have been a number of articles and guidelines put out about what we should drink, when we should drink and how much we should consume. Most of these have been pretty rough guidelines, and can generally be summed up as ‘water is good’. But as someone who has seen people become hyponatremia during marathons from too much water and an electrolyte balance … I know there are caveats with this as with everything else. So here are a bunch of things to remember as you kick off the fall marathon season!
- You need to drink 8 glass of water each day: this number is a ‘SWAG’ as the expression goes. The reality is that everyone has different needs, weather and environment impact your hydration, as does your activity level and how much water is in the food you eat. Conventional wisdom is now to let the early signs of thirst be your guide.
- Caffeine causes dehydration: while caffeine does have diuretic properties, in normal use they are very minor, and recent research shows that exercise after having caffeine provides more of a boost and doesn’t impact increased urination.
- Pure water is your best hydration source: Again, it depends. For general activity it is all you need – which is why ‘sports drinks’ are overkill in nearly all cases. But if you were doing a run like I did last weekend – 22 very hilly miles in heat and high humidity – you need to deal with the salt being lost through heavy extended sweating. In those cases you need an electrolyte drink.
- Hydrate until your pee is clear: generally this means you are actually overly hydrated and what is coming in is going out … the guideline is now that your urine should be ‘a pale yellow, like lemonade’ to indicate proper hydration.
- You can’t drink too much : this isn’t just wrong, it can be dangerous. As I mentioned, I saw people at half and full marathons who hadn’t maintained electrolyte balance and therefore suffered from hyponatremia, which is when your blood sodium gets dangerously low. You can actually die from this. There is a reason most endurance events offer both water and electrolyte drinks. Make use of them both to keep yourself safe.
- Proper hydration eliminates the concern of heat stroke: this is another possibly dangerous myth, especially for runners. You get warm when running, but in very warm temperatures your body can climb regardless of how hard you try to stay hydrated. Hydration is important – as is electrolyte balance – but if you don’t feel ‘right’ in a very hot situation, it is time to stop.
- Thirst isn’t a good indicator of hydration: aside from the obvious ‘I’m not thirsty now, so I should be fine to run 15 miles without a water bottle’, thirst is an EXCELLENT indicator. For athletes, you might need to ‘stay ahead of your thirst’ a bit to match your sweat rate, but that is something to learn over time.
- Drinking lots of water is a great ‘detox’ or ‘cleanse’: this goes along with the ‘pee clear’ thinking, in that by getting to the point where there is no color in your urine you are essentially ‘flushing your system’. That isn’t true, and recent studies show that excessive water can actually inhibit the ability of the kidneys to filter blood – the exact opposite of what you are trying to do!
The bottom line is common sense – keep water close by when you are active, if you are going to be doing strenuous work or exercise for more than an hour be sure to supplement with electrolytes, and most importantly listen to your body to avoid getting into serious medical trouble.
Are there other myths or bits of advice you have come across? Share them in the comments!