"Listen to your body" is a mantra that gets repeated a lot. By doctors, by physical therapists, by yoga instructors, and on running boards of all stripe.
The problem is...bodies are bullshit artists extraordinaire. Frankly, my body is a petulant 4 year old, and would like for me to do nothing save eat jelly beans and take hot showers for hours on end. Activities that are pleasant, but do little to advance my long term health. Bodies, you see, are focused on the short term.
This short term focus leads to a two level response by one's body to stress. First the body sends signals to the mind, encouraging the mind to do whatever it can to avoid the stress (the funniest example of this is how my nose always itches or my shoe feels loose before a hard track interval). When this doesn't work, and you do the workout anyway, then the body adapts to meet the needs of the stress. These two levels come into play in training all the time, as we work to push our bodies past the delaying tactics and into the place where we place stress and adapt.
By working out, we do a measured bit of destruction to our bodies, so that they can grow back stronger. Tiny muscle tears from a workout knit back in a way that is able to handle that stress in the future; a cardiovascular system that is overwhelmed develops additional capillaries and increases blood volume. Osteoblasts and osteoclasts work on bones to remodel them properly to handle the additional load. The key is to push the body hard enough to get to that adaptive level without pushing your body past the point where the destruction overwhelms it and it can no longer adapt. And part of this is constantly evaluating whether your body is telling you the truth when it sends you "can't do this" signals.
This delicate balance of just the right amount of physical strain and stress applies to general fitness development, but also to injury rehabilitation. In injuries, there's an acute stage, where the body part in question has been overwhelmed and needs to rest completely (hence no running and an aircast), and then a repair stage. During that repair stage, the body part needs a certain bit of intelligently applied stress to encourage it complete the process -- avoiding pain (heeding those delaying tactics and "listening to your body") means that you're stuck in limbo, and never quite heal.
(and this is where physical therapists shine -- in hand-holding one through applying just enough stress to complete the process).
In bone injuries, this repair stage includes remodeling. The raw material has been laid down, and "[r]emodeling of the bone occurs slowly over months to years and is facilitated by mechanical stress placed on the bone. As the fracture site is exposed to an axial loading force, bone is generally laid down where it is needed and resorbed from where it is not needed."
My foot is firmly in the remodeling stage. So, the trick for me, right now, is to put enough stress on the foot to encourage the bone to remodel itself to support the impact of running. I need to send the right signals to the foot, so that it refines the bone correctly -- if I don't send those signals, the bone will remain weak and unfinished.
But, I can't overdo it, or I overwhelm the remodeling process and go back down the rabbit hole into the aircast. The big trick is to figure out how much stress is enough but not too much. And at the same time, my foot, supported by my body, is arguing strongly for 100% jelly beans and hot tubs.
Hence the continuing dialog between me and my whiny foot. As my doctor warned me, my foot protests when I run. Not loudly, but I know it's there. And there's always the constant wondering of whether my foot's achiness and mild soreness (which again, I've been told to expect as part of the process) is just noise and complaining as I push it to the correct level, or an actual indication that I'm going too far.
And so I run a tiny bit every other day, paying close attention to what my foot is saying, assessing whether it speaks truth. It always aches when I run, but then improves. I take every other day off; when it ached on Friday evening after jogging Friday morning, I took that as a cue to rest it an extra 24 hours, delaying my next jog until Monday morning.
Was that the right call? I have no freakin' clue. All I really know is that there's a very fine fracture line between salvation and damnation here, and I don't trust the foot to tell me which direction is up.