How to drink enough water during exercise (Part 2)
So based on this, you know you need to drink water. Now the question is how much do you drink?
What is the standard? For the sake of argument, we’re going to say that one water bottle = one pint, by single water bottle I mean 16oz/473ml. I have water bottles that hold more but we’re going to use the smaller water bottles as benchmark. So this means that when you see some sports drink that advertises itself as 1 liter, you will know that it means about 2 water bottles full. You will also know that losing 1 pound (~.5kg) means about 1 water bottle in loss. One liter is about 2 pounds (~1kg).
The hole is larger than the spout. When you�re exercising, your body simply cannot replenish the electrolytes and calories at the rate you�re burning them. Evaporation from your sweat is much faster than you can drink. Later in this article we will discuss what happened in a study of ultra-marathoners who have tried to over-hydrate only to have hindered performance through a dilution of electrolytes and sodium, but we will discuss this later.
What you’re using. Using averages, you lose about 1 liter (2 water bottles) of fluid per one hour of exercise. When I go on a bike ride on our local and world famous American River Bike Trail, I generally ride between 2~3 hours, so from the time I leave my house to the time I get back, I lose about 3 liters of water; more if it emotional and clammy, less if its cold and dry. I’m in good aerobic shape so I have about 90 minutes of glycogen (sugar) stored in my muscles; if you’re in fairly decent shape, you have about the same. If not, you could take about 30 minutes off that. If you’re an ultra endurance athlete, you could add about 30 minutes to that time. If you’re a Lance Armstrong quality athlete, you could add another 15 minutes to that time.
“The endurance exercise outcome is to postpone Tiredness, not replace all the fuel, fluids and electrolytes lost during the event.” Dr. Bill Misner- Replacement vs. Replenishment
Under extreme conditions, you can absorb roughly 1 liter (2 water bottles) of water per hour. What I’m talking about here is the extreme maximum. During normal exercise, however, about half of that can be expected.
How much is too much? Just above I said you cannot drink enough to replace what you’re losing when exercising; however, you can drink too much. The reason is that since sweat contains Sodium Salt, you cannot drink Sodium water and have it absorbed into the body at the same rate you’re losing it. In a study done with ultra marathoners who tried to drink as much water as possible during a race, it was found that eventually a symptom called hyponatremia (low blood sodium) took effect. This symptom will collapse even an ultra endurance athlete. An even worse situation is a symptom called hypotonic (low blood electrolyte content) when there is not enough sodium or electrolytes, this is the big double whammy. A situation like this will put down even an ultra marathoner.
How to get it right. Since you don’t have a water gauge for too much or not enough on your body like I do on my Audi, a bit of trial and error is necessary. A general rule of thumb is between 20~25 oz/hr (590~740ml) is sufficient for generally people in good physical condition. So basically, about a water bottle and half per hour of exercise and you should be good to go. If you’re a light weight athlete and the weather is colder, then about 1 water bottle should be good. If you’re heavier and the weather is hotter, then up the ante. Use your best judgment and listen to your body. Don’t write me saying that you took my word as gospel. I’m not there to monitor you; what I�m giving you here is a general guideline.
So get out there, exercise and drink!
(By Charles Lloyd)
Tags: Sport