What sets people up to train for optimal distance-running performance? How much of this has to do with external factors (e.g., altitude, overall weather, people with whom to train) and how much relates to internal variables (e.g., typical mood, life "balance," job contentment, sleep habits)?
Obviously, the mix of elements leading to "ideal" training is different for different runners. That said, I'll emphasize three points here that I believe can be generalized to almost everyone, at least two of which are counterintuitive:
1. Conscious efforts to create ideal training conditions don't work especially well.
2. The things you might think would be very helpful at the elite level may not be.
3. Most people's window in this area is quite narrow, at least for unusually fast runners.
I am not going to pretend that the recipe that let me produce my fastest times -- which were nowhere close to elite but fast enough to generate some local-yokel-style attention and a handful of unimportant road-race wins -- would have done the same for everyone else. In my adult life, I enjoyed two stints during which I distinctly outperformed my previous and future efforts, the first coming at age 30-31 in 2000-2001 (mainly in the longer distances) and the other at age 34 in 2004 (at distances of 10 miles and below). During each of these, I was employed full-time and actually engaged in work activities for more than 40 hours a week between my day job and my freelancing. I was in a satisfying relationship. I wasn't sleeping much more than I ever have -- i.e., very little compared to most folks regularly logging well in excess of 100 miles a week -- but I wasn't an insomniac, wasn't depressed, and wasn't going on massive alcohol benders (that last one might seem obvious, but you might be surprised at how adroit some runners can be when to comes to balancing boozing and training in real time).
In my case, what allowed the fire to burn brightest for me was being sociable, being happy overall, and dealing with a dynamic slate of intellectual challenges (in 2000-2001 I was teaching and coaching at the high-school level, and in 2004 I was a medical research assistant in San Francisco). Had I ever had the luxury of not working and doing nothing but running a couple of times a day and filling the gaps in between with reading, playing video games, and watching movies or TV, I think it would have been a dubious luxury resulting in stagnation and poorer, not better, performances. Why do I believe this? Because I was actually pretty close to this "ideal" a few times, and all that happened is that I ran too much, fueled on boredom and general aimlessness and not really accountable to much outside of running itself.
Despite just outlining anecdotes suggesting that "balance" or at least a sense of balance is required for running success, I won't actually make that claim. In the training that produced a 1:08:29 half-marathon in October 2000 and a 2:24:17 marathon six months later, I was running twice a day, almost every day, up to (and once, during a school vacation, even over) 140 miles a week. This sometimes meant sneaking in a run at lunchtime and again at 8 or 9 p.m. in the deep freeze of a New Hampshire winter, or sometimes meant running with the kids at practice at 3 p.m. and deciding in advance whether that day's second run would happen before this or afterward. I had lesson plans to create and papers to grade, a dog to take care of, a girlfriend to spend time with and articles to write semi-regularly for Running Times. There was nothing inherently "balanced" about this by most sane standards. My girlfriend was a saint and frequently put up with me being gone at times of day most couples spend together (I tried to make up for it on weekends, at least, but Saturdays were often claimed by coaching at all-day track meets).
Shorter version: Being very good at something, or trying to, typically obliterates quaint notions of "balance." Something has to give, and every time I have been relatively fast, this has come with at least mild regrets over necessary sacrifices in other areas -- less reading, less TV, and so on.
Without intending to, I suppose I have addressed #2 above while leaving #1 and #3 untouched for now. A teaser for next time, and the rationale for the title of this post: Most runners stumble across the sort of schemes that work best for them rather than designing them, and it's usually not so much the addition of positive factors that allows them to maximally thrive, but the removal of negative ones.