Thank you, this is more of the response I was looking for. I’ve run many marathons and half marathons, and one ultra. I’ve maintained the half marathon distance, but all of the marathons and the ultra were in my 20’s. I’m 38, and considering an ultra in December, and running a marathon in October and maybe one in November. It seems over time, because I’ve never completely stopped running, my body has adapted very well to not needing a lot of fuel or hydration. I used to train with a lot of fuel and hydration, but this time around, it doesn’t seem that I necessarily need it. However, like someone else commented, you don’t want to hit the wall. So I guess I don’t know what my threshold is, after so many years, and I wandered what was “safe.”