in essence, i've come to understand 'junk miles' to be additional or extended workouts without any real perceived workout purpose that interfere with the athlete's ability to successfully tackle prescribed training tasks.
the problem that junk miles present is that they are often used to pad not only a weekly mileage total but the runner's ego. while races create the situation for a competition for the fastest time, training cycles can create the situation where individuals compete for the most miles (or in my case kilometres) logged. online trackers like dailymile, runkeeper and strava can feed that competitive nature by posting analytics on your social media outlets as a means of teasing, taunting or challenging your friends. while good 'king/queen of the mountain' feelings may result, the collateral damage is that when it comes to hard, speed-based workouts the energy and effort may not be there because resources were deployed to satisfy inflated distances.
now coming from a loosey-goosey, stream-of-thought kind of person like me you might be surprised to hear that i'm a fan of structured training. having used training plans from the hansons and ryan hall i've now found that i like to have a program to outline the different types of workouts (e.g. tempo runs, easy/recovery days, speed intervals, hill sprints, race pace) that i need to build into my cycle. however, also having read matt fitzgerald's book run i've come to believe that there's nothing wrong (and everything right) with listening carefully to feedback from your body and adjusting any training plan on the fly.
since i feel like i have the freedom to tinker, and having gained a sense that i do flourish under higher-mileage training conditions, i do tend to add the odd kilometre here and there as well as tossing in the occasional double (aka second training run in a day) or workout on a scheduled off-day.
rationale? (or in a more declaratory tense, "irrational!"?)
- one of the primary principles driving the hansons marathon method is that of cumulative fatigue, which suggests that (successfully) executing hard workouts on tired legs not only nets greater muscle/aerobic/mitochondrial gains but also simulates the late stages of the marathon - thereby preparing you to be able to overcome the dreaded 'wall'.
- in run (and other articles) matt fitzgerald alludes to the fact that time spent practicing the running motion improves communication between the brain and the muscles - this is all about developing skill through repetition. appreciating this helps me to see that the more kilometres (over months and years) that i log will refine my muscle memory for efficient running form - as long as i'm not running in such a fatigued state that my running form breaks down.
so while some might consider these 'junk miles' for me since they are not included on the 'printed' plan, in my estimation the extra kilometres and/or easy runs are not entirely without purpose.
if you'd like to check out more on this junky debate, here are a few resources worth reviewing:
so what are your thoughts? are you like me - do you fill up on junk?