All About Electrolytes

I read this interesting piece of information on Scott Dunlap’s blog about electrolytes,

“During exercise, the body loses fluids and sodium through sweating. This causes a decrease in blood volume, thereby increasing sodium and chloride concentrations in the blood. The increased concentration of electrolytes in the blood through decreased blood volume is what triggers the thirst mechanism. By the time an athlete becomes thirsty; the electrolytes are already out of balance, so restoration of blood volume is critical for the prevention of dehydration. Water consumption is effective in increasing blood volume; however, there is a consequential dilution of sodium in the blood due to the increased blood volume and excessive sodium losses in sweat, so electrolyte replenishment is key.”

So drinking water is not really enough if you are doing any kind of endurance training or competing, because you are then only diluting your already depleted suply of electrolytes.

The source of this interesting piece of information is Dr Shawn Dolan.
Dr Dolan also says

 If your training sessions last longer than 1 hour, choose a sport drink with adequate electrolytes as part of your fluid replacement program. If training sessions last longer than 2 hours, consider drinking an endurance specific sport drink. Hydrating with water alone can lead to water intoxication and an electrolyte imbalance.

Do not make any drastic changes to your diet for the days leading up to the race and on race day. Drastic changes can adversely affect your electrolyte balance. Prior to race day, introduce an electrolyte drink by sipping on it so your body is fully prepared to accept the drink during the race.

If you do long distance running, or any kind of endurance sport, it is definitely a good article to read.