Running isn’t always easy, and neither is learning the sport’s language in the beginning. Training terms are one thing. But abbreviations can be head-scratchers. Knowledge is power, though, and once you’re familiar with them, they’ll make sense—for the most part anyway.

Here’s a handy reference guide, so you aren’t left saying “WTF?!” when a friend says, “My BQ time was a PR by 5 minutes. Looks like upping my MPW really helped!”

PR: Congrats! A PR is your personal record at any specific distance. You may also hear, or use, the term PB (personal best).

CRThis stands for course record, as in the fastest time on a set course.

NRA national record is the fastest time ever recorded by citizen of a specific nation at a specific distance.

OR: An Olympic record is the quickest time set in an event in the Olympic Games.

WRWorld records are the fastest time ever posted for a given event.

DFL: Finishing dead f-ing last should be worn as a badge of honor. A finish is a finish, and is way more of an accomplishment than not starting in the first place.

DOMS: Running friends tend to have short-term memory loss when it comes to the delayed onset muscle soreness that kicks in the day after a race or big training day. You’ll most likely find yourself avoiding steps for a while, but it will eventually go away on its own. Look at it as a reminder to take it easy after your hard effort.

DNF: Even the most carefully planned race efforts can go awry. And sometimes you have to call it quits. The DNF listed in the results means “did not finish.” Learn something from the experience and move on.

DNS: Life, injuries or a less than stellar training cycle may keep you from the start line of a race you are registered to run. If that’s the case, you’ll see this abbreviation, meaning did not start, by your name. There’s always next time!

LSD: Long, slow distance runs are a training plan staple when preparing for longer events like half marathons and marathons.

MPM: Minutes per mile represents how many minutes it takes you to run a mile. There is no right number here, only what works for you! And no, you do not have to hit a certain MPM to be considered a “real” runner.

MPW: For those of you who track your steps, you are probably familiar with the idea of miles per week. Your weekly mileage total, which will fluctuate during a training cycle, gives an indication of your base and endurance. If you have a coach, this is something they’ll want to know.

BQ: A Boston qualifying time is your ticket to run the Boston Marathon. The specific time needed depends upon your age and gender, and varies from year to year. Go to the Boston Athletic Association’s website to learn more.

FKT: Some runs and trails aren’t made for races, but you can still go fast. The fastest known time on each route is the one to beat and compare yourself to. Most us, though, are more inclined to set personal FKTs.

GPS: The Global Positioning System’s ability to track your location and movement has become so known by its acronym that relatively few people spell it out anymore. The technology is a common feature on many running watches.

RICE: Rest, ice, compression and elevation are the initial go-to treatments for most running injuries.

XT: Cross-training exercises are non-running-based activities, like swimming, yoga and cycling, that help to improve overall fitness.

HR: Heart rate is how many times your heart contracts in a minute. Since it’s the measure of BPM, beats per minute, you may also see it referenced as such.

HRM: Sure, you can check your heart rate using your fingers at a pulse point, but a handy heart rate monitor (wrist based or a chest strap) can do it for you.

MHR: Maximum heart rate is the fastest heart rate an individual can achieve. For hard training runs, you’ll sometimes be instructed to workout at 60 to 85 percent of MHR.

RHR: Resting heart rate is the number of times your heart beats per minute while at rest, like when you first wake up in the morning. It will vary depending upon fitness, fatigue, age, gender and overall health.

VK: Vertical K or vertical kilometer race, an uphill trail race that sends runners 1,000 meters up a trail as steeply as possible. (The actual horizontal distance of a vertical K race will range from 2K to 5K, depending on the slope of the trail.)