Triathlon Terminology: One Glossary to Rule ’em All

 October 3, 2015

By  Mikael Eriksson

Triathlon terminology: Glossary of triathlon terms, acronyms and abbreviations

Triathlon terminology can be overwhelming sometimes.

In this up-to-date glossary you'll learn what all those confusing triathlon terms really mean.

Acronyms and abbreviations are also included.

This glossary is continually updated, so don’t hesitate to comment if you feel that there are additional swim, bike, run and triathlon terms that should be in here.




Half distance triathlon. “Half Ironman”. 1.2 mile swim, 56 mile bike, 13.1 mile run (half marathon). Also a trademark (owned by WTC, World Triathlon Corporation), so not all half distance races are official 70.3 races.

Active recovery

Very low intensity exercise or activity after hard training or racing, e.g. easy cycling.


Short for aerodynamic. Something to shoot for on the bike. Your position can be aero, your wheels, your bottle, your bike etc.


Bars attached to the front of your bike, allowing you to lean down and over and ride in an aero position.


Used to describe workouts of low enough intensity that the muscles can derive all required energy from the oxygen delivered to them from your lungs via your heart. There is no build-up of lactic acid in your blood.

Aerobic threshold

The point at which exercise is just possible without significant lactic acid accumulation. In running, roughly standalone marathon pace.


General term for non-professional triathletes. Triathlon race results are typically divided into different age groups.


When the oxygen delivered to the muscles cannot break down glycogen and produce energy fast enough, lactic acid starts to accumulate, and is used as a complementary enegy source. This energy system is less efficient than the aerobic system, and cannot be maintained for as long periods of time.

Anaerobic threshold

The point at which lactic acid accumulates faster than the body can remove it. In running, the pace you can just maintain for 60 minutes in a race situation. Corresponds to FTP.


An unofficial (sometimes official) race class for women over 150 lbs. See also Clydesdale.


Refers to training base or base period. Your general fitness level upon which you can add more and more specific fitness as you get closer to a goal race. The base period is when you do a lot of aerobic training to improve your endurance. Learn more here!

Beach start

When a race starts from the beach and you run into the water.

Big day

A training day usually consisting of a swim, a long ride and a run (usually with a small food break thrown in somewhere) adding up to many hours. Among the most important “workouts” in an Ironman build-up.

Body marking

Some races require you to have your race number marked on your body (upper arm, lower leg) with a marking pen or a temporary tattoo.


Hitting the wall. Running out of energy and feeling like there’s no way in hell you can continue. The physiological reason for bonking is depleted glycogen stores.

Breathing pattern

Used mostly in the swim, but also in running and even biking. In swimming, breathing patterns can be categorized as uniateral (always to the same side) or bilateral (to both sides), and further specified to e.g. 3-stroke (breathing on every third stroke) and 4-stroke (every fourth) patterns etc.


Workouts combining two or more disciplines. Often a ride followed by a run.


A training period after a base period. The build is typically when you start adding more intensity to your training.


Colored floating markers for an open water swim course. See pull buoy for swim training tool.


The number of swim strokes, pedal revolutions or steps per minute in your swim, bike and run. Corresponds to RPM (revolutions per minute) in cycling.


The set of cogs at the rear wheel hub. Used for gearing. Learn more about cycling equipment and gear.


The first of three underwater phases of your swim stroke after your hand enters the water.


See cooldown


The two cogs that transfer the power from your pedalling via the chain to the back wheel. Used for gearing. 


An unofficial (sometimes official) race class for men over 200 lbs. See also Athena.


Short period of very easy swim/bike/run at the very end of your workout to bring your heart rate down and set you up for a quicker recovery.


An well-known and established organization of 60+ full and half distance races all over the world. Competitior to WTC.


Attached to the bottom of your bike shoes, allowing them to lock into clipless pedals. Learn more about cycling equipment and gear.

Clincher wheels

Regular bike wheels. Compare to tubular wheels. Learn more about cycling equipment and gear.

Clipless pedals

Locking mechanism that connects the cleats on your shoes to the pedals so you’re locked in, and can transfer power evenly throughout a pedal revolution since you’re pulling up as well as pushing down.

CO2 cartridge

Used with an inflator to fill your tube instantly with CO2 instead of pumping air furiously for minutes by the side of the road.

Compression gear

Socks, calf sleeves etc. that apply gentle pressure gradients to improve blood flow. Have been shown to speed up recovery, and many swear by them even in training and racing.


Component that moves your chain from one chainring to the other or from one sprocket on the cassette to another. Learn more about cycling equipment and gear.


Dead fucking last…

Disc wheels

Solid wheels designed to be aero. Often used as race wheels. Learn more about cycling equipment and gear.


Did not finish.


Did not start.

Dolphin dive

Technique for entering the water fast where the water is too deep to run but too shallow to swim.


Two workouts on one day.


In the swim and bike (draft-legal races only), you can draft behind other athletes to reduce drag and wind resistance and save energy.

Draft zone

In non-draft races, an imagined rectangular area of varying size (depending on race) surrounding each bike which must not be entered by other competitiors except for when they are passing you.


Common in both swimming and running, but also cycling. Excercises designed to improve your technique in one or a few particular focus areas for that drill.


Salts that are essential for your body. Includes e.g. sodium, potassium, chloride and calcium.


An event (typically pre-race) for checking out featured vendors and exhibitors, getting deals (some great and some not so great) and free giveaways, and hanging out with other athletes.


A workout that consists of non-structured intervals.

Flip turn

A fast way to turn at the end of a swim length and push off against the wall to go back the lane in the opposite direction.

Floating start

A race start where you start in the water, treading water.

Foam roller

A tube of foam (or harder materials) that you can use for myofascial release to improve muscle recovery and release sore spots.

Foot strike

The way your foot hits the ground when you run. Typically categorized as forefoot, midfoot or heel-strike.


Swim technique used in triathlon. The most efficient form of swimming. See this Get started guide for beginners to swimming.

Front crawl



Functional threshold power. The highest average power you can hold for one hour. Usually approximated based on shorter test protocols, such as 20- or 30-minute tests.


A source of energy (mostly simple sugars) that are fast absorbed and thus optimal for workouts. Squishy texture and come in all sorts of flavours.

Goodie bag

A bag with all sorts of free stuff, including edibles, that you get when you participate in a race.

Half Ironman

See 70.3

Hand entry

The phase of the swim stroke where your hand enters the water.

Heart rate monitor (HRM)

A device (typically a belt with a transmitter) that measures your heart rate which is then shown on your watch or bike computer.

Hill reps

Hill repeats. Bike or run workout where you repeatedly go up a hill at a high intensity level.


Heart rate.

Indoor trainer

A training tool which allows you to set up your bike indoors and train. Use a mat under it, or the sweat pools could cause serious water damage to your floor!


Type of training where you alternate periods of higher intensity efforts with periods of easy or recovery effort.


A full distance triathlon. 2.4 mile swim, 112 mile bike, 26.2 mile run (marathon). Also a trademark (owned by WTC, World Triathlon Corporation), so not all full distance races are official Ironamn races.


International Triathlon Union. A union of national triathlon federations. Organiser of the World Triathlon Series, which is the world series for Olympic distance triathlons.


A cycling top. Has useful large back pockets for stuffing stuff you need on your ride.


The action of kicking in swimming, and overarching term for kicking drills (e.g. using a kickboard with and without swimfins)


Swim training tool made of styrofoam held out in front of you for kick practise.


Venue in Hawaii for the Ironman World Championships (IWC).


Negatively charged compund which is formed as a waste product when the body produces energy anaerobically.

Lactate threshold

The point at which lactic acid is just beginning to accumulate. Contrary to popular belief, not quite the same as the anaerobic threshold (although they’re close).

Lactic acid

Somewhat misused term referring to the hydrogen ions (acid) produced in parallel (but not in the same biochemical reaction) as lactate. These hydrogen ions cause the burning feeling in muscles during intense exercise.


An interval workout with increasing and decreasing interval distances/durations, such as swim intervals of 50 – 100 – 150 – 100 – 50 m


Local bike shop

Long course

Although no official definition exists, usually seen as race distances longer than Olympic distance (or half distance and longer)


Long slow distance. Term for aerobic endurance training.


Short for lubricant. Used both for bike maintenance and on the body for preventing chafing.

Main set

The focal part of a workout, often the whole workout minus warmup and cooldown.


Pedalling at a low cadence in high gear

Negative split

When the second half of a race or workout is faster than the first.

Non-draft race

A race in which drafting is not allowed. Learn more about the most important rules in triathlon here

Off-road triathlon

A triathlon off-road, with open water swim, mountain biking and trail running.

Olympic distance

The race distance of the Olympics and the World Triathlon Series. 1.5 km swim, 40 km bike, 10 km run.

Open water swim

As it sounds, swimming outside of the safe confines of the pool. (You can practice it in the pool, though.)


Open water swim


Training aid for swimming. Plastic paddles attached to your hands that increase water resistance so they help build strength and can also increase awareness of technical errors.


Personal best.


Training period just before the taper, where you get really specific for your goal race and try to reach your peak fitness.


Drafting in non-draft races and other rule violations are penalized with added time, or with being stopped for a certain time before being allowed to continue.


A season is typically divided into several different periods. This is referred to as periodization. A typical progression could be base, build, peak and taper periods before a goal race.

Plyometrics (Plyo)

Various forms of jump exercises. Often explosive, bulding strength, power and balance. Learn more here.

Positive split

When the second half of a race or workout is slower than the first.

Post-race beer

Self-explanatory, but it should be noted that although the expression is in singular, the implementation rarely is.


Measured in watts (W) and calculated as force times velocity. Used mostly in biking where it is measurable (force applied to pedals or crank arms times the angular velocity of pedaling). In contrast to heart rate, power is a direct measure of output.


Personal record.


Inward rolling motion of foot after foot strike.


The second underwater phase of the freestyle stroke.

Pull buoy

Floating swim training tool placed between legs to keep your legs up so you can concentrate on your stroke.

Pull float

See pull buoy


The final underwater phase of your stroke. (For a stroke analysis video, see here.)

Race belt

Elastic belt used to keep your race number in place without having to pin it to your clothes.

Racing flats

Lighter and “faster” running shoes saved for races and speedwork.


Recovery can mean: recovery after workouts, racing or training blocks. Recovery within workouts. The overwater phase of your swim stroke.


Often used interchangeably with intervals. Can also be used for example in strength training descriptions, e.g. squats – 10 reps.

Rest interval

The recovery time/distance between the intense intervals in interval workouts.


Rest, Ice, Compression, Elevation. Common remedy for niggles, sore muscles and general recovery.

Road bike

A “regular” road racing bike. Compare to Tri bike. Can be equipped with aerobars for closer resemblence to tri bikes. Learn more.


Rate of perceived excertion. A subjective rating of intensity and effort level. See this RPE-table.


Revolutions per minute. See cadence.

Short course

Although no official definition exists, usually seen as race distances up to Olympic distance.


The act of quickly lifting your head and checking the direction towards the next buoy in an OWS.


Broad term for high intensity intervals


Pedaling at a high cadence in low gear


Time for a specific discipline or transition in race/workout, or segment of a discipline.

Sprint distance

The shortest triathlon distance. An official sprint consists of a 750 m swim, 20 km bike and a 5 km run.In smaller local races this can vary, though.


Strides or pickups are accelerations of 10-30 seconds up to close to maximum speed done during warm-ups before races and speedwork, and as part of technique sessions where focus is on good running form.


Outward rolling motion of foot after foot strike.


Transition one, from swim to bike.


Transition two, from bike to run.


Short period before the race where training volume is decreased so accumulated fatigue disappears just in time for the race without losing too much fitness due to decreased training volume. Can easily lead to madness.


See anaerobic threshold, lactate threshold and aerobic threshold.

Time trial

A non-draft bike race in aero position.

Timing chip

Chip attached around ankle that times you in races when you cross timing mats at start, finish and splits.

Tire lever

Small tool used to remove the tire from your wheel to replace or repair the inner tube.


The change from one discipline to another (see T1 and T2).


Triathlon bike. Differs from a road bike in frame geometry (mainly seat tube angle) for easier transition to running, and in that it has aerobars for optimal aero position.


See Time trial

Tubular tires

Lighther than common clincher tires. Tubular tires are stitched around the inner tube and then glued to the wheel rim. This can make mid-ride repairs tricky, but tubulars are quite puncture resistant.


The maximum rate of oxygen uptake and utilization in the body. Very common fitness measure.


Easy exercise or movements at the start of a workout/before a race to get the blood flowing and get the muscles primed and prepared for the coming effort.

Wave start

Race start format where not all competitors start at the same time. Rather, they are divided into start “waves”, and there is a certain time between the start of each wave.


World Triathlon Corporation. Owner and organiser of Ironman and 70.3 races.


See warm-up


Can refer to heart rate or power zones specifically (e.g. as %-range of maximum HR/power), or general training load zones. Several zone systems exist, but one commonly used system is to use the following zones; recovery, aerobic endurance, aerobic threshold, anaerobic threshold, anaerobic

Mikael Eriksson

I am a full-time triathlon coach, founder of Scientific Triathlon, and host of the top-rated podcast That Triathlon Show. I am from Finland but live in Lisbon, Portugal.

Please contact me if you have feedback on the podcast or want to make suggestions for improvement or send in a question for a Q&A episode.

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  • Great list. I came here looking for the differences between the terms: 1. an Out & Back, 2. Single Loop, or 3. Multiple Laps on the bike or run.

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