The runner's glossary, to shine at the aid station

In short Over thirty running words, from taper to VO2 max, explained simply (with a bit of humour) so you never nod along without understanding again.

Before we start

Ever heard someone say "yesterday was threshold, today's easy, and Sunday I've got a long run with plenty of climbing"? It's not a secret code, just runner vocabulary. Here it is, from A to V, without needless jargon.

From "aid station" to "fartlek"

• Aid station: the table with water and often food. Home of crushed cups and very short conversations. And now the perfect place to use the words in this glossary.
• Blister: a small pocket of fluid under the skin, caused by friction. Its best friends: new shoes, wrinkled socks and badly placed seams. If it's big, very painful or looks infected, ask a pharmacist or doctor.
• Bib: the number that identifies you, usually worn on the front, clearly visible, fixed with pins or a race belt. Don't fold it, don't hide it under a jacket: the organisers want to see it, and so do the photographers.
• Cadence: the number of steps per minute. Your speed is your cadence multiplied by your stride length. As simple as multiplication, only more breathless.
• Chicken legs: the affectionate nickname for many runners' skinny calves. At Leg Up, it's a compliment.
• Chip: the small transponder, often stuck to the back of the bib or tied to your shoe, that records you crossing the timing mats. Thanks to it, your real time starts when you cross the line, not when the leaders set off.
• Cool-down: the few minutes of slow jogging or walking after a session, to come down gently. The sporting equivalent of not slamming the door on your way out.
• Corral: the start area where runners are grouped by target time. Lining up in your dream-time corral rather than your real-time one guarantees being overtaken all morning.
• Cut-off: the time by which you must pass a point on the course to be allowed to continue. Very common in trail running, it exists on the road too. The one appointment of the day where being early is truly rewarded.
• DNF: "Did Not Finish", a retirement in the results. Its cousin, DNS ("Did Not Start"), covers those who never started. Neither is shameful: sometimes stopping is the smartest decision of the day.
• Easy run: a run at a relaxed pace where you can hold a conversation. It makes up most of the training of most runners. If you can describe your holidays while running, you're there.
• Elevation gain: the sum of all the climbs on a course. On trails, distance and gain are announced together: "30 km and 1,500 m of climbing", and everyone understands it won't be a stroll.
• Fartlek: a Swedish word meaning "speed play". You vary the pace freely with the terrain and your mood: speed up to the lamp post, recover to the bench. Intervals, playtime edition.
• Finisher: anyone who crossed the finish line. The word is English, the pride is universal.

From "gel" to "pacer"

• Gel: a small sachet of concentrated carbohydrates to swallow during effort, often with some water. Test it in training: an unknown gel on race day is a lottery for your stomach. Flavours range from "fine" to "intriguing".
• Headlamp: the light you wear on your head to run at night, often compulsory on long trails. Check the battery before you go, not in the middle of the forest.
• Hill repeats: the session where you run fast uphill and recover jogging or walking down. Great for strength, much less so for morale on the fifth rep.
• Intervals: a session alternating fast sections and recoveries, for example 10 times 400 m. The word that makes some runners' eyes shine and others turn pale.
• Max heart rate: your maximum heart rate in beats per minute. Ready-made formulas like "220 minus your age" only give a rough estimate; a stress test with a sports doctor actually measures it.
• Negative split: running the second half of a race faster than the first. The holy grail of patient runners, and the exact opposite of what start-line excitement whispers to you.
• Pace: the time it takes to cover a kilometre, in minutes per kilometre (for example 5:30 per km). Not to be confused with speed, in km/h. The smaller the number, the faster you go: one of the few areas where you dream of your numbers going down.
• Pacer: in elite races, a runner who sets the pace for part of the race, often stepping off before the finish. In mass races, pacers run for an announced target time, often with a flag or balloons, and you follow them like a mountain guide.
• PB: "Personal Best", your best time over a distance. No need for a world record to raise your arms: yours is enough.

From "rented calf" to "VO2 max"

• Rented calf: at Leg Up, a calf wearing a brand's temporary tattoo on race day, at the price set by its owner, which earns money once the proof is validated. The only calf that makes a living by running.
• Long run: the longest session of the week, at an easy pace, the backbone of half and full marathon training. It lasts a long time and often ends with a well-earned brunch.
• Splits: intermediate times, per kilometre or per section. Your watch announces them, sometimes with brutal honesty.
• Stride: the way you land and chain your steps, and by extension the length of each step. No point copying a champion's: better to evolve yours gently.
• Taper: the period at the end of a training block when you cut volume sharply while keeping some intensity, to arrive fresh on race day. The hardest phase of the plan: you have to do less, and not crack.
• Tempo: a continuous run at a sustained pace, close to threshold, for a set time (for example 20 minutes). Less brutal than intervals, harder than easy running: a happy medium… not exactly comfortable.
• The wall: the sudden slump that lies in wait for many marathoners, often around the 30th kilometre, generally linked to running out of glycogen (the sugars stored in muscles and liver). A sensible starting pace and good fuelling during the race help avoid it, or at least make it lower.
• Threshold: a sustained intensity, often described as "hard but controlled", beyond which fatigue builds much faster. Threshold sessions teach the body to hold a sustained effort for longer. Talked about a lot, suffered a little.
• Trail: racing in nature, on paths and tracks, with climbing. You walk the hills without shame, eat at aid stations without guilt, and come home muddy up to the knees.
• VO2 max pace: the speed at which you reach your maximum oxygen uptake, often called "VMA" by French runners. You can only hold it for a few minutes, and it's the basis for interval paces. To estimate it, the half-Cooper test: run as far as possible in 6 minutes, then divide that distance in metres by 100 to get your VO2 max speed in km/h (1,500 m gives 15 km/h). Do it rested, well warmed up, and after medical advice if you have any doubt about your health.
• Warm-up: the 10 to 20 minutes of easy jogging, mobility and progressive strides before a hard session or a race. The one you skip when you're late, and regret in the first kilometre.

The last word

You're all set. Next time someone mentions a negative split at the 25 km aid station, you can nod knowingly, or even slip in a casual "fartlek". And if someone asks why your calf has a logo on it, you now know the technical term.