Let’s talk hydration!
We can go for three minutes without air, three days without water and three weeks without food. So, staying continuously hydrated seems to be a no brainer. Water serves as an integral part of the body and has important roles such as:
· Carrying nutrients and oxygen to your cells
· Regulating blood pressure
· Aiding digestion
· Preventing constipation
· Cushioning joints
· Maintaining electrolyte balance
· Regulating temperature
A common rule that many of us try and follow to stay hydrated is to drink 8 cups of water a day. But where did this rule come from? Well the myth that we need 8 glasses a day likely originated from a study conducted by the U.S food and nutrition board in 1945, where they recommended 2.5 litres of water a day. People took on board that advice without taking into consideration that the fluid recommendation included water that was naturally contained in food. People continued to follow this adage, even though till this day there is no research to show that 8 glasses is the optimal amount.
Maybe instead of following this old and arbitrary rule, why don’t we trust in what has worked for us for thousands of years, our body’s thirst response. We should let our body guide us, drink when you are thirsty and don’t ignore what your body is asking. Yes in certain conditions we need to drink more so than usual, such as when you have a urinary tract infection or diarrhea, or in some medical conditions we need to restrict fluid intake such as people with congestive heart failure, but let your general practitioner decide on that.
Using the colour of your urine is a more robust way to look at your hydration needs. Your urine should be light yellow, if it looks like water you’re drinking more than you need, if it is dark yellow or even orange you need to drink more.
Staying hydrated whilst exercising
While the risk of dehydration is well known and documented, it is possible to become overhydrated during exercise leading to a condition known as exercised associated hyponatremia (EAH). EAH is mainly associated with sporting events lasting more than 2 hours, so sports such as hockey, basketball and soccer would not be at risk. Hyponatremia is a condition where there is low salt concentration. During prolonged exercise excessive sodium loss can occur through sweat, coupled with many athletes consuming more water than is needed causes the concentration of salt levels in our blood to drop leading to EAH.
In 2002 the dangers of overhydration became known when a 28-year-old collapsed during the race and died two days later due to EAH. In subsequent years Harvard Medical School conducted studies and found that around 13% of Boston marathon runners had hyponatremia, with the strongest predictor of hyponatremia was due to excessive fluid intake. In fact, athletes who collapse from heat illness during exercise are often quite well-hydrated.
So how do we avoid this? Well because sodium is lost in sweat, it is very important for those are preparing for a marathon to get adequate sodium before, during and after exercise, especially if they continually drink water. As a safeguard during intensive prolonged exercise drinking fluids that contain sodium can help. However drinking sports drinks can only help slightly, with EAH mainly related to the total fluid intake during exercise.
The key is to simply drink when you feel thirsty, this be during exercise or day to day life. It isn’t necessary to stay ahead of your thirst. Try and have a glass of water with each meal and use the colour of your urine to decide whether you need another glass of water.