I had a really crappy run on Wednesday morning, which I attribute to the fact that I donated blood the night before and was not at the top of my game. But, it did make me think more about fueling for runs, or, more specifically, fueling DURING runs.
Until recently, I didn't have running shorts/tights with a pocket. And I don't really know about running with a belt (chafing!), and I don't like to hold anything in my hands while running. This has meant that I've never fueled during a run. Never had a drink during a run. While this is probably not a big deal for the majority of my runs, which are under 10km, it's likely been detrimental to my 15-20km runs.
There are a few different options for fueling during a run, and a lot of it seems to be personal preference, and a combination of weather and distance you're going.
Hydration - General rule of thumb, according to Run The Planet, is ~750 mL for every hour of activity.
Electrolytes - If you're running for over an hour, you'll need to replenish your electrolytes. Core Running has a breakdown of all the electrolytes you need, if you're curious, but I usually just have G2 when I get home from a run.
Gels/Chews - Gels, being closer to a liquid, are more easily absorbed than chews, which should be taken with water. The gel/chew choice really depends on what you like.
This summer I'll hit up MEC for an assortment and give them a try during my longer runs and hikes!