At some point, all healing injuries reach the point where physically, it's tough to discern if the body is actually completely healed or if the pain has subsided, while the actual healing needs more time to continue. Many times, the end of pain of discomfort truly marks just the halfway point of the healing. Like your body is saying, "OK, the fire is out, but it's still smoldering."
I have no idea if running injuries are significantly different than other sports injuries in this respect, but I doubt it. At some point your body is OK enough to function without pain, but maybe not OK enough to function at running or jumping or absorbing tackles, etc.
That point int he healing process is probably the riskiest, as it's very easy to give into the temptation of "well, it's been 3 days and it doesn't hurt. I'm sure 3 miles today will be OK. Just three miles..." I mean, maybe for some people this approach works out and they run 3 miles without any trouble and that's that. I'd guess for more of us, myself included, this is merely our mind playing the role of The Empire at the Battle of Endor: lure us in with the appearance of normalcy, only to spring the trap ("It's a trap!") and bring the pain back about a mile into the run.
That was my main concern following a frustrating week where my knee/upper leg hurt, but not terribly and felt fine after two days, only to then hurt again after I ran last Friday. Obviously, my mind had laid the trap and I'd fallen right into it, like Admiral Akbar and the rebel fleet. So, I resolved to shut the whole thing down for a full week, committing to not running again until this recent Saturday. My hope was that since the pain wasn't severe, I hadn't been quite stupid enough to create a much worse situation for myself right at the best running time of the year, and that a week of rest with some stretching and icing would provide the break needed to heal fitfully.
Thankfully, I can report that at this point, that seems to be the case. After two short, easy runs this weekend of 3 miles apiece, the leg feels OK and I've had no pain during or after each run. I had just a touch of stiffness yesterday after the run, but I iced the spot and stretched my calf muscles out and used a foam roller that my wife got me for my anniversary (awesome!) and that helped tremendously.
Today, I did the same route: a bit over 3 miles. I started at an easy pace but the leg felt really good so I gradually dropped my pace until I was around 8:30 or lower (my pace averaged 8:45 per mile for the 3+ miles) to test it a bit more. No issues at all, which was a huge relief.
So, that discipline of not trying to deviate from the plan and jumping back into running mid-week seems to have paid off. I'm still going to my sports medicine doctor appointment on Tuesday for a couple reasons. First, I made it a week ago, so I might as well keep it. Second, I want to be sure, after describing the pain and the recovery, etc., that there's nothing else I should be doing or no other possible injury I should be considering. Better safe than sorry.
Now, I've mapped out a gradual return to where I was before the injury, minus the foolish speedwork. Rest tomorrow (Monday), then 4 miles on Tuesday followed by rest on Wednesday, etc. I'll plan on a short 7.5 or 8 miler next weekend, and if all goes well, will be back working toward increasing my mileage more gradually after that. The biggest shift will be largely abandoning the speed workouts for now.
I'm going to just live with being a bit slow for a while, especially since I need to gradually increase my mileage for my planned major race target in May of next year: the Flying Pig's Skyline 3-Way Challenge. The challenge is to run the 10k and 5k on the Saturday of the running festival in Cincinnati, and then either the half or full marathon the next day. I'm going to do the half, obviously, but that will still be a bit over 22 miles of running in less than 24 hours, so my winter will be spent getting my endurance up to the point where I can aim for fast (for me!) times in all three races. I don't want to just survive those races; I'd like to tackle them in good shape.
All of which is to say, navigating this niggling injury such that it doesn't become a more significant challenge to my running in the short term is key. I think taking the week was the right thing to do for sure; now I just have to stick to the gradual increase in training to make sure I avoid any setbacks.
