Option 3: Sports Drink
As I mentioned above, some runners are unable to comfortably consume 60 grams of carbohydrates per hour while running. If you're among these runners, then you should just aim to take in as many carbohydrates as agrees with your tummy. You can still use a scaled-back version of Option 1 or Option 2 to meet your individual needs, but you might find it easier to get all of your fluid and carbs from the sports drink offered at aid stations.
Provided you're at least able to drink as much as the average runner during races, you will be able to get 30 to 40 grams of carbs per hour by drinking a sports drink according to thirst and stomach comfort, which isn't too bad.
Option 4: Water
In any given marathon, approximately four percent of marathon participants suffer from severe gastrointestinal symptoms. A majority of these runners are unlucky people with sensitive stomachs who often experience GI problems while running. If you are such a runner you may not be able to consume any carbohydrates in your marathons, yet you may still be able to limit dehydration by drinking water according to your thirst.
It's a lot better than nothing. A study done by English researchers found that subjects were able to sustain moderate-intensity exercise for one hour and 17 minutes on average when they drank nothing. With plain water, they were able to last for one hour and 43 minutes.
More: Fluid Facts for Athletes
Option 5: Nothing
Some runners with sensitive stomachs are unable to tolerate even plain water in races. Is it even possible to run a marathon without drinking anything? Yes. Until the late 1960s, runners seldom drank during marathons, and even today some very accomplished marathon runners drink little or nothing when they race. For example, Shalane Flanagan drank only four ounces (about two swallows) of Gatorade during her debut marathon in New York City in 2011. She finished second.
If you are a runner with a sensitive stomach, there are a couple of tricks you can exploit to minimize your disadvantage in marathons. I share them in my latest book, The New Rules of Marathon and Half-Marathon Nutrition.marathon.