More Endurance for Your Marathon Run

So, today I had an 8 mile run. I ate a not too ripe banana about 40 min before leaving along with a little honey and load of water. My run came in at 8:39 per mile. Good for me, but was it the right thing to be eating for endurance tomorrow with a 13 mile run?

So, I wanted to find some research on hte right foods to eat. The latest research suggests that you want a low Glycemic Index (GI) diet for sustained energy on your longer runs and marathons. Here's some current research:

"Low GI foods have been proven to extend endurance when eaten alone 1-2 hours before prolonged strenuous exercise. In a study reported in the International Journal of Sports Nutrition, cyclists who ate lentils as a pre-event meal were able to cycle at 65% of their maximum 20 minutes longer compared to cyclists on a pre-event meal of regular white potatoes. Cyclists on the lentils had higher levels of blood sugar and insulin after 90 minutes of exercise. This demonstrates that the carbohydrate sugars were still being absorbed." Read the whole article "Glycemic Index and Glycemic Load." So much for ripe bananas (thought they say less-ripe banana are actually low GI) and honey tomorrow.