Running glossary
Plain-English definitions for the terms you’ll run into registering for, training for, and running a race, each broken into the specific questions people actually ask.
A 10K is a road race covering 10 kilometres, or 6.2 miles. It's one of the most common race distances, popular with beginners testing themselves beyond a 5K and with experienced runners chasing a fast, focused time.
A 15K is a road race covering 15 kilometres, or about 9.3 miles. It sits between a 10K and a half marathon, giving runners a longer endurance test without the full commitment of 21.0975 km.
A 5K is a road race covering 5 kilometres, or 3.1 miles. It's the most beginner-friendly standard race distance and the usual starting point for new runners and run clubs.
A half marathon is a road race covering 21.0975 kilometres, or 13.1 miles, exactly half the distance of a full marathon. It's one of the most popular race distances worldwide, demanding enough to require real training but short enough to fit into a single season of preparation.
A marathon is a road race covering 42.195 kilometres, or 26.2 miles. It's the longest standard race distance most runners train for, and finishing one is widely treated as a major running milestone.
A relay race splits a course distance, such as a marathon, among a team of runners, with each member covering one leg before handing off to the next. It lets a group cover a long distance together without any single runner running the whole route.
An ultra marathon is any race longer than the standard marathon distance of 42.195 kilometres. Common ultra distances include 50K, 50 miles, 100K, and 100 miles, and they're often run on trails rather than roads.
A virtual race lets runners complete a set distance on their own course and schedule, then submit their time or GPS data to the organizer. It removes the need to travel to a start line while still offering a bib, a result, and often a finisher medal.
An aid station is a supply point along the race course offering water, electrolyte drinks, and sometimes snacks or medical support. Spacing varies by event, but longer races typically place them every few kilometres.
Bag drop is the baggage service at a race that lets runners check a bag of belongings before the start and collect it after finishing. You typically hand it over at a marked truck or tent near the start using a numbered tag matching your bib. It's meant for essentials like warm clothes, a phone, and post-race snacks, not valuables.
A bib is the numbered tag runners pin to their shirt to identify them during a race. It usually carries the timing chip, and it's what officials, photographers, and aid station volunteers use to recognize each runner.
Chip time is the time it takes a runner to complete the course, measured from when they personally cross the start line to when they cross the finish line. It's tracked by a timing chip built into the bib or attached to the shoe.
A corral is a designated starting pen that groups runners by expected pace or bib category before the race begins. It helps large races start in an orderly way, with faster runners nearer the front so slower runners don't create an early bottleneck.
A cutoff time is the maximum time allowed to complete a race, or to reach a specific checkpoint, before organizers close the course. Runners who don't meet it may be pulled off the route, moved to the sidewalk, or denied an official finish.
DNF stands for Did Not Finish, the result recorded when a runner starts a race but doesn't cross the finish line. It can happen due to injury, illness, missing a cutoff, or simply calling it a day. It shows up in official results instead of a finish time.
DNS stands for Did Not Start, the result recorded when a registered runner never begins the race. It's different from a DNF, where the runner starts but doesn't finish. Injury, illness, and travel issues are the most common causes.
The finish chute is the fenced, funnel-shaped pathway runners pass through right after crossing the finish line. It keeps the flow of finishers organized while volunteers hand out medals, water, and food.
Gun time is the total elapsed time from when the starting gun fires to when a runner crosses the finish line, regardless of how long it took them to reach the start line itself. It's also called clock time, and it's the standard used to determine overall race winners.
The medical tent is the on-site first aid station at a race, staffed by doctors, physiotherapists, or paramedics. It's usually set up near the finish line, with smaller aid posts along the course for urgent cases. Any runner can walk in, and marshals will bring in anyone who looks unwell.
A pacer, sometimes called a pace bunny or pace setter, is an experienced runner assigned to finish in a specific target time, like 4:00 or 5:30 for a marathon. They usually carry a sign or balloon showing their goal time and run at an even pace runners can tuck in behind. Following a pacer takes the guesswork out of pacing yourself.
A race expo is the pre-race event where runners collect their bib and race kit, usually alongside stalls from sponsors and running brands. Most organized races require in-person bib pickup at the expo rather than on race morning.
A sweep vehicle, also called a broom wagon, is the vehicle that follows the last runners on the course at the official cutoff pace. Any runner it overtakes is usually asked to stop running and board it so roads can reopen on schedule. It marks the back edge of the race, not a judgment on the runner.
A wave start releases runners in separate groups at staggered intervals rather than all at once. It's used in large races to ease congestion at the start line and along the early part of the course.
Cadence is the number of steps you take per minute while running, counting both feet. Coaches often reference a range around 170 to 180 steps per minute as a general guideline, though the ideal number varies with a runner's height, pace, and natural stride.
Cross training means doing non-running activities, like cycling, swimming, or strength work, to build fitness while reducing the repetitive impact of running. It helps runners stay fit, manage fatigue, and lower the risk of overuse injuries.
Easy pace is a relaxed, conversational running speed used for the majority of training miles, well below race pace. It should feel comfortable enough to talk in full sentences without gasping for breath. Most of a runner's weekly mileage, often 70 to 80 percent, is meant to be run at this pace.
Fartlek is Swedish for speed play, an unstructured training run that mixes fast and slow segments based on feel rather than fixed distances or times. Unlike formal intervals, there's no set plan, you might surge to a landmark then jog to recover, all within one continuous run.
Interval training alternates short bursts of fast, hard running with periods of easy running or walking to recover. It's used to build speed, running economy, and aerobic power in a structured, repeatable way. Most training plans schedule it once or twice a week, never on back-to-back days.
The long run is the single longest training run in a weekly schedule, usually done at an easy, conversational pace. It's the backbone of endurance training for half marathons and marathons, building the stamina and mental toughness needed to cover race distance. It's typically run once a week, often on a weekend.
A negative split means running the second half of a race faster than the first half. It's widely considered a smart pacing strategy because it involves starting conservatively and finishing with something left in the tank, rather than fading late.
A recovery run is a short, slow run done at an easy, conversational pace after a hard workout or race to promote blood flow without adding real training stress. It should feel deliberately easy, not like a workout.
Tapering is the planned reduction in training volume in the final one to three weeks before race day, while keeping some intensity. It lets your body recover from months of training and arrive at the start line fresh, not fatigued. Mileage usually drops gradually rather than stopping all at once.
A tempo run is a sustained effort at a comfortably hard pace, faster than easy running but not an all-out sprint, usually held for 20 to 40 minutes. It's designed to raise your lactate threshold, the pace you can hold before fatigue builds up quickly. Runners often describe the effort as hard but controlled.
Carb loading is the practice of eating extra carbohydrates in the days before a long race to maximise glycogen stores in your muscles and liver. The goal is to start the race with a full fuel tank so you're less likely to run low on energy late in the race.
Chafing is skin irritation caused by repeated friction, usually from fabric rubbing against skin or skin rubbing against skin, common at the thighs, underarms, and nipples during long runs. It's prevented with lubricant or anti-chafe balm and well-fitted, moisture-wicking clothing, and it gets worse the longer you keep running without addressing it.
DOMS, short for Delayed Onset Muscle Soreness, is the muscle stiffness and tenderness that shows up 24 to 48 hours after unusually hard or unfamiliar exercise, like a long run or a race. It's a normal response to muscle stress, not an injury, and it usually eases within a few days.
Electrolytes are minerals like sodium, potassium, and magnesium that your body loses through sweat and that help regulate fluid balance, muscle function, and nerve signals. Runners often replace them with sports drinks, gels, or salt tablets during long or hot races to help avoid cramping and dangerously low sodium levels.
Hitting the wall describes the sudden, severe fatigue runners feel in a race, most often in a marathon somewhere around the 30 to 35 kilometre mark, when the body's stored carbohydrate runs critically low. It shows up as heavy legs, foggy thinking, and a sharp drop in pace.
Runner's knee, medically known as patellofemoral pain syndrome, is a general term for pain around or behind the kneecap caused by repetitive stress and poor kneecap tracking during movement. It's one of the most common overuse complaints among runners and usually builds up gradually rather than from a single incident.
Shin splints, medically called medial tibial stress syndrome, is pain along the shin bone caused by repetitive stress on the muscles, tendons, and bone tissue around it. It's an overuse issue that tends to build gradually, often after a sudden increase in mileage, intensity, or a change in running surface.
VO2 max is the maximum rate at which your body can take in and use oxygen during intense exercise, measured in millilitres of oxygen per kilogram of body weight per minute. It's one common marker of aerobic fitness and is often used to estimate race potential, though pacing, running economy, and mental toughness matter too.
A certified course is a race route that's been independently measured and verified to be an accurate distance, using a standard set by an athletics federation. Certification confirms the course isn't short, which matters for record eligibility and personal best comparisons. It's usually noted on the race website with a certificate number.
A course marshal is a volunteer or official stationed along the race route to direct runners, manage traffic and crossings, and watch for anyone in distress. They mark turns, keep the course clear, and are usually the first point of contact if something goes wrong. Their instructions on course should always be followed, even if they conflict with your GPS route.
Elevation gain is the total amount of uphill climbing on a course, measured by adding up every rise from start to finish. It's usually given in metres and is a better indicator of course difficulty than net elevation change alone. A hilly marathon can have a low net elevation change but still demand a lot from your legs.
A loop course starts and finishes at the same point by running one continuous circuit, or the same shorter circuit repeated multiple times. It's common in city marathons because it keeps road closures contained to a single area. Multi-loop formats also make it easy to place aid stations and cheer spots that runners pass several times.
An out-and-back course runs in one direction to a turnaround point, then retraces the exact same route back to the start and finish. It's popular because it only needs one road corridor closed and a single start and finish area. Runners typically cross paths with the leaders and the back of the pack along the way.
A point-to-point course starts in one location and finishes in a different one, rather than looping back to the start. It often allows for a net downhill or scenic route that wouldn't be possible with a loop. Runners usually need to arrange transport to the start, since it's a separate location from the finish.