A couple weeks ago, in this very space, I wrote about the reasons why I started running back in high school and why I continue to lace up my running shoes today. Over the years, I’ve evolved from uber-competitive athlete, to quasi-competitive runner to, in the past few months, a runner with no real racing goals who simply aims to get out the door at least once a day for anywhere from a few minutes to a couple hours.

As I explained in that entry, most days I try to run for an hour; sometimes, however, I only get out for 30 minutes, while on other days I’m not able to run at all. In fact, the no-running-at-all days for a while were more frequent than I cared to admit, but they were mostly due to long travel days, sickness or some combination of the two.

Recently, however, I’ve found myself getting out to run on a pretty regular basis, and have had the good fortune of running with a slew of different people nearly every day, including my fiance, the athletes I coach, friends, co-workers looking for a running buddy, as well as former training partners who need someone to beat on, I mean share the workload with during their tough workouts.

Over the course of a given week, I might tag along with a group of local marathoners for their Sunday long run, jog easily with a coworker the next day at lunch, pace my fiance and her training partner during 2-mile repeats on Tuesday morning, jump in a tempo run with some my athletes the following day to make sure they don’t fall off pace, run my friend’s marathon-simulation workout with him on Thursday, jog by myself on Friday, and then join my fiance for her 4-hour bike ride followed by a 4-mile transition run on Saturday, despite not having ridden for four weeks prior.

Yes, I have become everyone’s Workout Mule. (Note: some folks might use the name of another animal to describe someone who plays this noble role, but I’d rather be called a mule. Not only is it less offensive, it’s a also a more accurate job title. Thanks to Drew Wartenburg, fellow Workout Mule and director of cross country and track at UC Davis, for the turning me on to the term.)

So, what exactly is a Workout Mule? Glad you asked. He — or she, Workout Mule, Inc., is a fictitious equal opportunity employer — is perhaps the most important person in the day-to-day life of a competitive endurance athlete in training. A Workout Mule is a service animal with no immediate goals of their own, and is available on a moment’s notice to pace parts of a grueling workout, lend encouragement in the most difficult and dire of situations, carry fluids when needed, or simply give a lonely athlete someone to talk to during a long training session.

The role of Workout Mule is not one to be taken lightly. It’s important that a Mule always show up on time, run the right paces, not drop water bottles and be willing to run faster and farther than they had planned should the situation necessitate. Athletes in the midst of serious training rely on their Mule for support and encouragement when workloads are heaviest, and as such the Mule must be ready for everything and anything.

Mules are willing to sacrifice their own plans for a given day (and often their own best interests, too) with little to no hesitation so that others can benefit from their assistance. These animals are usually unpaid, but will never turn down some free schwag, a swig of sports drink, small bite of an energy bar or an appreciative high five.

Have you thanked your Mule today?