Running on EMPTY....

Since I am completely fascinated with running and how the human body reacts to it, I take great delight in treating myself as a lab rat. I know it sounds crazy to the average person but fellow runners will completely understand this operational mode. The past few weeks I have been trying something new as part of training and experimenting. I have been intentionally running on "empty" (very little to no fuel, just electrolyte drinks and coffee at wake up time). I have been trying to train myself to run on "empty" so that it accelerates fatigue and I want to see how my body reacts to this adjustment. What I am finding is that yes there are definitely days I am dragging more during a run because I need fuel, but there are other days I feel completely fine. For example, today I ran 15 miles on NO FOOD (just drinks) and I was fine. My pace wasn't fast but I wasn't trying to be fast - on purpose. I hovered in the 11's and occasional 12's. Last week I ran 15 miles and I ate a protein bar ahead of time, and I'm not convinced it really helped me then either (maybe because I was running so damn slow?!). I only ate it because I thought for sure I would NEED IT before the end of the run. Well today I elected to have NO FUEL and I ran about the same. I wasn't crushing it but I'm not trying to right now. I'm in the middle of many long mileage weeks (5th week of over 50 miles) so I am definitely at a point of fatigue (and I weirdly love it). My goal is to do this in training so that when I get to the marathon and I have fuel at designated time points, having food THEN should REALLY help me. (I compare this running on no fuel to a baseball player swinging a weighted bat during batting practice so when they get to the actual game, they can swing more effortlessly. Since I want to run more effortlessly on race day with REST and FUEL, my thought is to train by running with no fuel during peak training weeks so the fatigue and effort is at an all-time high. (Of course, if I felt terrible and like I needed to eat, I definitely would!) When it is race day, I take fuel very seriously and don't care if I eat too much. Like most marathoners, I force myself to eat breakfast and definitely take in the GU at certain miles (and/or more often if I feel myself slowing down). I have often wondered about races where I have slowed... "What if I ate an extra GU? Would that have helped me run faster?" I am sure it would have but at the time, I brushed it off and thought I was good to go without it. (During marathons, I have had as little as 5 GU packets and as many as 7 or 8. I usually take them at ~5, 10, 13, 16, 19, 22 and optional one at 24 - I usually skip because by then it would take too long to kick in. Depending on the race, I have adjusted to intake GU earlier or later depending on how I feel.) Right now during training, it is fun to experiment and see what your body can handle. My runner friends and I always talk about how people ACTUALLY THINK they NEED so much more food than they actually do. We run A LOT and WE DO NOT even need THAT much food!! True, we are not giant people either but still. Runners tend to really think about the food they are putting in their bodies because food actually has a purpose - to help you literally "run" as an efficient machine!