I like to stop at a convenience store during my long runs and buy a cola. Everyone else is drinking water or sports drink. They give me a hard time for drinking soda. Is there anything wrong with drinking cola on long runs?
Soda is sugar water .. . just like a sports drink. To make soda into a sports drink, dilute it in half with water and add a dash of salt (or munch on a few pretzels alongside the soda). The sodium (salt) enhances fluid retention.
Soda such as cola offers 100 calories per 8 ounces; Gatorade offers about 50 calories per 8 ounces. Both have few nutritional merits. Because a sports drink is more dilute than cola, it is easier to absorb and will empty quicker from the stomach. Hence, during intense runs, or in hot weather, when rapid fluid absorption is important, you might want to drink water alongside the cola to dilute it.
The caffeine in cola may be one reason you prefer it over a sports drink. Caffeine, particularly in combination with carbohydrates (i.e.,the sugar in soft drinks), is known to enhance performance. Although once thought to have a dehydrating effect, we now know that it not true.
As long as the cola settles well, without creating belching or stomach aches, you have my blessing to enjoy it during extended exercise. It is just one way to consume the 200 to 300 calories from carbohydrates you need per hour of running. The cola will help you maintain high energy and enjoyment of the run.
Granted, a wholesome breakfast or healthier pre-run snack to fuel the first hour is nutritionally preferable to relying on sugar-water. But during extended exercise, sugar in any form will help keep you from hitting the wall. The guidelines are to limit your sugar intake to 10% of your calories. That's 200 to 300 sugar-calories per day .... that means, one soda during a long run is OK but four sodas for meals and snacks is another story.