The Soggy Sock: Building Mileage

Written by Dr. Christina Schultz, DPT

Mileage is at the crux of any training program. Whatever training philosophy you ascribe to, there is some type of mileage or time build.

A necessary challenge: mileage builds are where we see the most running injuries, but they’re key to some extent for everyone. Even if you are not building to a marathon or ultra and don’t need to hold a performance pace for an extended period of time, we all need to increase our aerobic efficiency to round out our training.

Every race above 800m depends on more than 50% aerobic energy systems

And the more efficiently we work at levels that depend on aerobic systems, the better, for two reasons. There are multiple ways you can manipulate your training to improve your aerobic efficiency, which we’ll discuss later, but building mileage is often the first step, so we’ll discuss that strategy today since every run program involves it at some point.

Couch to 5k? You have to start at 0 and build up. Finished a marathon? You (should) take several weeks of recovery and then ramp back up. Always ran 5ks and now you want to dabble in the marathon? You have quite the build ahead.

For my marathoners out there, keep in mind that there are diminishing returns after a 3-hour run: typically we don’t see significantly increased cardiovascular benefits, we have a much harder time recovering for the next training session, and we see a much higher risk of injury past that point.

So how do we do this safely?

A few rules of thumb

1. Don’t exceed a 10% increase in volume from the week before.
2. Have a variety of distances planned throughout the week, with a designated “long run day” that in most cases makes up 20–40% of your weekly volume.
3. For every 3 “up” weeks of mileage, have a 4th “down” week to allow your body to recover and adapt.

It’s important to note that these rules have significant limitations

• This only looks at your previous training week to determine how much more you can do each week, but your body could still be feeling the effects of a hard training week further back.
• This doesn’t take into account the intensity of the work you did, only distance or time.

That’s why I prefer to use ACWR (acute:chronic workload ratio) with my athletes when I can, and you can too, though it will require a lot more math on your part. We’ll cover exactly what that is and how to use it in a future issue.

But for both those using ACWR and those who are not: ultimately your body has the final say. Even if the numbers say you should be able to do a workout, and you feel like something is off that day, listen.

I always tell my athletes that the mark of a great athlete is the ability to listen to your body and respect what it’s telling you. This will set you apart from everyone around you: more in tune, peaking well, playing to your strengths, and built for longevity.