Just like any other sport, running has its own unique lingo. For anyone new to the running community (or even some veteran runners or supporters), these terms can be quite confusing. This guide will cover some of the most common lingo used by runners. Consider this your own personal Duolingo lesson in running language.

5K: A race that is 5,000 km or 3.1 miles long.

10K: A race that is 10,000 km or 6.2 miles long.

Aerobic Exercise: Cardiovascular exercise that is typically done at a relatively low heart rate and taps into the aerobic energy system, using oxygen to produce energy and burning primarily fat stores for energy. When running, this should be done at a comfortable, sustainable, and conversational pace. Example workouts include easy runs, MAF runs, recovery runs, and most long runs.

Aid Station: Points along a race route that provide fuel or hydration for runners. These often include a sports drink and water and, for longer distance races, energy gels or other fuel.

Anaerobic Exercise: Cardiovascular exercise done at a higher intensity/heart rate than aerobic exercise. During this type of exercise, your body’s oxygen requirements are higher than what is available and the anaerobic energy system is activated, utilizing primarily carbohydrate as a fuel source. Example workouts include tempo runs, fartleks, speed intervals, and sprints.

Boston Qualifier: A race that has been approved by the Boston Athletic Association (BAA) to be used for submitting qualified times for entry into the Boston Marathon.

BQ: A Boston Marathon qualifying time. This is an official marathon time that allows someone to qualify for entering the Boston Marathon. The time requirements are updated annually and achieving a BQ does not necessarily guarantee entry into the Boston Marathon. However, this is a major achievement and common goal for many marathon runners.

Cadence: Also known as stride rate, it’s the number of steps a runner takes per minute. A higher cadence is often associated with more efficient running form, however, each runner has their own unique optimal cadence rate. It is generally accepted that a cadence over 164 steps per minute (SPM) is ideal for injury prevention.

Chafing: Skin that has been irritated by clothing, gear, or other skin from rubbing during running over longer distances.

Corral: A grouping of runners of similar paces at a race. Typically, faster runners will be in a higher corral (starting closer to the start line) with walkers and slower paces lining up toward the back. This keeps traffic flowing and prevents back-ups of runners and congestion, especially in the first mile or two of a race.

CR (Course Record): This can be defined as either: a) the fastest time in which a runner has run a particular course; or b) the fastest known time for which any runner in a given division, or overall, has run a particular course.

Cross Training: Other forms or exercise outside of running such as swimming, cycling, strength training, yoga, etc. Some forms of cross training can be extremely beneficial to your running performance, others may pose more of an injury or overtraining risk. Be sure to discuss any cross training with your coach.

DNF: Did Not Finish. This term is used when someone starts, but does not complete a race.

DNS: Did Not Start. This term is used when a runner does not start the race.

Fartlek: A Swedish term meaning “speed play.” It’s a form or training that mixes continuous running with intervals of different speeds and intensities. Fartleks are typically unstructured, where interval workouts have a defined structure. An example of a fartlek workout is to pick up the pace during the chorus of a song, or sprint between every other street sign.

Fastest Known Time (FKT): The fastest time on record that a runner has completed a specific course. These are often not completed during official races, but run alone during solo-efforts and may include outside support.

Glucose: The form of carbohydrate that circulates within your bloodstream and is transported to muscles that require additional fuel.

Glycogen: The form of carbohydrate that is stored within muscles and liver. This type of carbohydrate is converted to blood glucose for energy during activity.

Half Marathon: A race that is 13.1 miles long.

Heart Rate: The rate at which your heart beats during a given time period. This is typically measured in beats per minute (bpm). Common heart rates used in running include:

1. MAF Heart Rate: Maximum Aerobic Function heart rate. This is used in recovery runs and in building aerobic base. (See MAF Run).
2. Max Heart Rate (MHR): The maximum rate at which your heart can beat. This can often be measured during a max-effort workout, a race, or during a test by trained professionals. This can be highly variable and often does not fit the standard 220-age model.
3. Resting Heart Rate (RHR): The rate your heart beats at rest. When referencing this heart rate, it’s often measured when you first wake up in the morning and/or have been in a resting/lying state for at least 10 minutes.
   

Heart Rate Zones: A measurement of the degree of intensity an exercise is or should be performed at.

1. Zone 1: 55-65% MHR, recovery & easy running
2. Zone 2: 65-75% MHR, aerobic training
3. Zone 3: 75-85% MHR, tempo
4. Zone 4: 85-88% MHR, lactate threshold
5. Zone 5: 88-110% MHR, anaerobic training

Hill Repeats: Fast, hard, sprint efforts run uphill for a given time period, with a recovery jog back down, then repeated. Hill repeats (also known as hill sprints) are a great way to build strength and speed.

Intervals: Repeated segments of fast running followed by periods of rest, walking, or slower running. This type of training helps improve both speed and endurance.

Lactic Acid: Lactate Threshold (LTR): The intensity of exercise at which lactic acid starts to accumulate in the blood. Training at or near this threshold can increase your ability to process or “clear” lactic acid at higher intensities and during races. LTR is approximately 85-88% of max heart rate.

Long Runs / Long Slow Distance (LSD): Long runs are the longest run of the week and are a key part of training. The length of the long run depends on the goal and prior training history of the runner.

MAF Run: A type of recovery run done with a general heart rate of 140-age as a max heart rate, although there are some modifications to this calculation. These runs promote recovery, improves aerobic function and fat utilization, and allow you to add mileage without additional strain.

Marathon: A race that is 26.2 miles long.

Negative Splits: A run completed progressively faster through the duration of the run, where each split is faster than the one prior.

Overpronation: When the foot rolls inward excessively upon landing. This can sometimes lead to injuries and may require stability shoes or, in extreme cases, orthotics to correct. It is important to note that a certain amount of pronation is normal and is part of an optimal running form.

Overreaching: A period during intense or peak training where training is near the maximally sustainable threshold. When an athlete is overreaching, they are building fitness but may experience a greater recovery need.

Overtraining: A status where training intensity has far outweighed the athlete’s ability to recovery properly - mentally or physically. Common symptoms of overtraining are overwhelming fatigue, injury, poor muscle recovery and/or injury, and mental burnout. Athletes are no longer building fitness while overtraining. This is a key differentiator between overreaching and overtraining.

Pace: The speed at which you run, typically measured in minutes per mile.

PR (Personal Record): the fastest time a runner has achieved in a specific distance.

Quality Sessions / Quality Workouts: Key workouts that include longer or harder efforts than easy and recovery runs. These include long runs, long run workouts, speed sessions, tempo runs, and Fartleks.

Race Bib: An identifying paper given to runners who have registered for a race that displays a race number and often includes a timing chip.

Recovery Run: A slow, easy run used to recover form harder workouts, long runs, and/or races.

Speedwork: Workouts prescribed to increase fitness and speed, completed faster than normal pace. These often include interval sessions or race pace efforts.

Split: The time it takes to complete a specific distance within a run. For example, a marathon race may provide split times at the 5K, 10K, half-marathon, and 30k marks. Other races may provide mile splits.

Strides: Short bursts of increased speed worked into a regular run, typically run for several very short intervals (such as 10 or 20 seconds). These work to increase leg mobility and lengthen strides without overtaxing the cardiovascular system and creating additional strain. These may be run during a routine week of training in one or more easy runs, and often are included prior to race day to keep legs fresh.

Taper: A reduction in the volume and/or intensity of training before a race to ensure peak performance on race day. The common timeframe for a taper is anywhere from 1-3 weeks before a goal race.

Tempo Run: A run completed at a sustainably hard effort that is less than a sprint, but harder than easy running. Paces for tempo runs will often be prescribed by your coach.

Timing Chip: A small tracking device, often taped to the back of a race bib, that records your time during the race. Time may be recorded only at the finish line, at both the start and finish line, or with splits along the way.

Ultramarathon: Any race distance longer than a marathon; over 26.2 miles.

VO2 Max: The maximum amount of oxygen your body can utilize during intense exercise. Historically, it has been thought that a higher VO2 Max correlated to better running performance, however, this is now being researched and debated.

Zone 2 Run: Running done at approximately 65-75% of your maximum heart rate. This type of run builds aerobic fitness, increases fat metabolization, and allows the addition of mileage with low risk of overtraining or injury risk. Exercising in this heart rate zone has also been proven to increase longevity and health span, vascularity within muscles, as well as the number of mitochondria within muscles.