I have mentioned this before, but it is a very important thing to know, so I am going to post it again!
As you begin running, your body has to go from a resting state to an active state. That first mile or two, your body will not be able to use as much fat metabolism for fuel, because it is not as quick. Fat metabolism is efficient for long slow efforts, but the ramp-up time is a bit longer.
So when starting, your body will pull the easiest fuel source it can get, which is always blood glucose!
Sometime a slow warmup will help reduce an early drop. As your body ramps up more slowly, it will not pull as much glucose from your blood and is able to use more fat metabolism.
The other thing you can do is just take a very small amount of initial carbs, right when you start.
Be careful on the starting carbs. After an hour of zero basal, if you take carbs and wait too long, you will spike!
So when I say to “take them right before you start”, what I am really saying is…
“take them RIGHT before you start!!!”
Not 10 or 15 minutes before!!!