The Runner’s Glossary

What does PR mean? (and other running terminology questions answered)

Last updated on February 8th, 2023

Like most sports, running has a language all its own. The meanings of most terms are obvious, but don’t be embarrassed if that reference or abbreviation doesn’t make sense to you. Just look it up! Here are a number of terms you’ll come across in the course (pun intended) of your running career.


5K – 3.1-mile run or walk

10K – 6.2-mile run or walk

Aid station – You can get water, Gatorade or Powerade, or medical attention at an aid station.

Bib – No, this isn’t an abbreviated vest to catch your spills (although that’s not a bad use for it after a race). A bib is the (hopefully waterproof) sheet a runner is given for a race. It always contains your number, and sometimes has your name, too. It’s typically pinned onto an article of clothing, worn on the chest (or back, or sometimes at the waistband). Sometimes the timing chip is embedded in the bib (see chip timing); this is how race organizers know how long it took you to run the race.     

Carbo loading – When you eat a lot of spaghetti or bread (or both) during the day or days leading up to a race.

Chip timing – Races that use chip timing embed a timer in either the bib or a strip of plastic that runners attach to one of their shoes. The timer starts when you cross the start line and stops when you cross the finish line. Translation: You don’t have to worry about being 3 minutes “late” for a marathon. Your chip won’t start timing you until you cross that start line. So yes, you have time for the porta potty.

Corral – Corrals are set up at some races to group people who run approximately the same pace. If you’re in corral 17 and you run an average 10-minute mile, look around. The other people in your corral run about the same pace. This keeps slower runners out of the way of the 5-minute-milers.

Course – This is the terrain you’ll be covering during the race.

Cross-training – Cross-training is doing exercise other than running in preparation for a running event. For example, you might cross train by swimming, biking, hiking, jumping rope, or walking.

Duathlon – This type of event starts with running, then switches to cycling, and then ends with running again. Don’t fancy yourself a swimmer? Then this might be perfect for you. 

Elevation – How many feet do you ascend and/or descend during a run? That’s the elevation of a course. My younger sister cried when she first saw the elevation map for a San Francisco 26.2-mile run. It turned out to be her best marathon, and she’s run 10 of them. So don’t jump to conclusions. It might not be as bad as it looks on the map.  

Elites – Professional runners who win marathons and other endurance sporting events. They start races earlier than the rest of us. But take heart: Sometimes they poop their pants just like me and you.

EP – Easy pace

Expo – A running expo is a pre-race extravaganza where runners pick up their bibs, get their free T-shirts, sample free food, and sometimes enter drawings to win free cars or other exciting prizes (my sister once won a loaf of Oroweat bread, and I was pretty damn jazzed for her). Expos for Sunday races are usually held on Friday and Saturday of race weekend.

Fartlek – After you run a warm-up mile, a fartlek workout is a run of any distance with fast surges (about a minute long) throughout. Fartlek means “speed play” in Swedish.

Finisher – You finished a race. You didn’t get a leg cramp at mile 2 and go home defeated. You got a leg cramp at mile .002 AND you kept going and eventually crossed the finish line. Yay, you!

Flat course – My favorite. This course has few or no hills. Mommy like.

Gels, chews and “goos” – These can be a runner’s best friend when taking on longer distances. They might not sound appetizing, but these small, easily transportable packets filled with “goo” (usually consisting of sugar, carbs and electrolytes) provide your body with the calories (read: energy) you need to get you across the finish line. They also come in “chews,” which is nice if you like to have something to chomp on while you run.

Good body day/bad body day – When, despite thorough analysis, you can’t figure out why you had a good run or a bad run. The good body day/bad body day theory (trademark my running friend Diane) explains it all. Some days are good body days (GBD); some days are bad body days (BBD). Period.

Half marathon – 13.1-mile run

Interval running – Alternating short, intense bursts of running with equal or slightly longer amounts of time running a slower pace.

Ironman – A very long-distance triathlon, usually consisting of a 2.4-mile (3.86K) swim, a 112-mile (180.25K) bicycle ride and a marathon (26.2-mile or 42.20K) run, raced in that order.

Kid’s run – It’s a run for kids. Let’s get the next generation into this!

Marathon – 26.2-mile run

Mud run – You’re running in the mud some or all of the time.

Pace – Your time per mile. Elites regularly run 5-minute miles. On good body days (see definition, above), I run 10-minute miles.

Pacer or pace team – These runners lead a pack of runners whose goal is to finish a certain course under a certain time. A marathon pace group might carry a sign that says 3:00, which means their goal is to finish in three hours or less.

Plantar fasciitis – A common runner’s foot injury that can result from inflammation of the plantar fascia ligament or tears in the ligament due to repeated strain.

PR – This stands for “personal record,” or your best time running that particular distance. For instance, my PR for a half-marathon–which I’m very proud of, but you may snicker at–is 2:00:37, or just over two hours. Give me some credit. I’m 52, and at least I didn’t poop my pants.  

Pronation/overpronation – Pronation is a natural part of everyone’s gait. It occurs as the foot rolls inward and the arch flattens. It provides shock absorption. Some runner overpronate, which means their foot rolls inward too much. This can cause injuries, as can oversupination, the opposite of overpronation.

Race weekend – Pretty self-explanatory. The Friday, Saturday, and Sunday of the race. Some say the race weekend festivities (carbo loading, the nervous pinning of bib on shirt, the shameless post-race eating) is more fun than the race itself.

Ragnar Relay – A 12-person relay team covers 200 miles from point A to point B in two days. May involve running at night and sleeping in front of a Subway (the sandwich place or the mass transit option).  

RP – Race pace

Spartan Race – Teams of at least 4 people run an obstacle course, frequently involving scaling hills, mountains, and walls.

Splits – Splits divide a run or a race into smaller parts to help your measure your pace. For example, you might divide a six mile run into six separate mile splits. You could also divide the six mile run by 2 and run 3 mile splits which work well for out-and-back runs. Running a negative split means you ran the second half of a run faster than the first.

Sprint triathlon – A short-distance triathlon, usually consisting of a 750-meter swim, a 20K bike ride and a 5K run.

(Standard) Olympic triathlon – A long-distance triathlon, usually consisting of a 1500-meter swim, a 40K bike ride and a 10K run.

Stride – The average length of your steps.

Supination/oversupination – Like pronation, supination is a normal part of your gait. It occurs when the foot rolls outward. However, like overpronation, oversupination can cause injuries.

Trail run – You’re running in the dirt some or all of the time.

Triathlon – See standard triathlon

TVUU (Toilet View Urination Urge) – When you have to go to the bathroom during a run, but when you find a restroom and make eye contact with the toilet, the situation instantly becomes a “pee-mergency.”