Triathlon can be a daunting sport at the best of times, but not knowing the difference between a DNS and a DNF or what a 70.3 is could make it even harder to feel part of the community. We're here with all the triathlon vocabulary you need so that you can mount your TT and calculate your VO2 and FTP with confidence.

How To Speak Triathlon

Aero Bars – These are bars that you can fix onto your road bike in order to achieve the elusive 'aero position' which allows you to ride faster. Aero bars are relatively inexpensive and are a good alternative to buying an expensive triathlon bike. Aero bars are not allowed in most cycling road races and are usually exclusive to multisport racing (in duathlon and triathlon mainly). 

Aero Position – Many serious triathletes will spend hours perfecting their aero position so as to ride as fast as possible on the bike section of the race. You can achieve the aero position by resting your forearms on your tri bars or aero bars. This is a notoriously difficult position to maintain and requires a very strong back and core as well as concentration to control the bike. It is not recommended to hold this position while navigating a technical course.

Sundried sponsored athlete Conal McBride holds the aero position while competing.

Age Group/Age Grouper/AG – Triathlon races and results are categorised into gender and age group so that athletes can compete fairly against people of the same gender and similar age. If someone wins their Age Group, it means they came first out of the people in that category; there may have been hundreds competing or there may only have been one other!

Elites or Pros compete separately, regardless of age. Age Group triathletes are amateur athletes who do not get paid but are at the top level for their age; professional triathletes cannot compete in Age Group competitions.

In Britain, the following age groups are applied to BTF races:

AquaBike – For those who have an active imagination, an AquaBike is not some sort of amphibious bicycle. An AquaBike is an event with only a swim and cycle section, ideal for those who aren't keen on running. 

Australian Exit – This is a type of exit found in open water races with multiple laps. The competitors will exit the water after one lap, run on land around a marker or monument and then get back into the water to swim another lap. The Australian Exit is popular for spectators as it creates such a sight and allows family and friends to cheer on athletes as they exit and re-enter the water. 

Bonk/Bonking – Otherwise known as “hitting the wall.” If you bonk during a training session or race it means your body has run out of glucose and you are running on empty. It may also be down to dehydration and/or not taking on enough electrolytes. Bonking can take many forms, from feeling light headed to physically not being able to move. It's important to nail your nutrition and hydration strategy to avoid bonking. 

BOPer – An acronym for 'Back Of Packer' which refers to someone who frequently races or finishes in the Back of the Pack.

Brick/Brick Workout – A brick workout is a training session where you do two different disciplines back to back, usually cycling followed by running. These sessions are crucial to performing well in triathlon as running off the bike can be notoriously difficult and getting your legs used to it is vital for not getting caught out by jelly legs on race day.

BTF – The BTF is the British Triathlon Foundation and is the governing body for triathlon in the UK. 

Cadence – More commonly known among laymen as RPM< or revolutions per minute. Your cadence is the rhythm of your swim stroke, bike pedalling, or running stride. A higher cadence when running would mean taking more steps, a higher cadence when cycling would mean pedalling more quickly, and so on. 

Century – A 100-mile bike ride. Many cyclists and triathletes consider riding a century to be an important milestone. 

Century, Metric –  A 100km (62-mile) bike ride.

Cleat – The part on the bottom of the cycling shoe where your shoe attaches to your clipless pedals. You can read our cleat guide here.

Clipless Pedals – Pedals installed on your bike that allow you to “clip in” your shoes. Some people do not feel confident 'cycling clipless' as there is the danger that you could topple over if you do not unclip before your bike comes to a stop. However, if you have the confidence, riding clipless will allow you to increase your power output and therefore ride faster and more efficiently. 

Criterium (Crit) – A criterium is a cycling race which consists of cycling several laps of a tight and often technical closed course, usually in city or town centres. 

DFL – Acronym for “Dead F***ing Last”. It is no shame to finish DFL in a race. 

DNF – Acronym for “Did Not Finish” (the race). An athlete can have a DNF for any number of reasons, from bike mechanicals to illness or injury. 

DNS – Acronym for “Did Not Start” (the race). Many triathletes consider a DNS to be worse than a DNF, because with a DNF at least you gave it a go. 

Dolphin Kick – Kicking your legs in unison when swimming. Athletes will often do this just after diving into the pool before they resurface and begin their stroke.  

DQ – Acronym for being disqualified from a race.

Drafting – In cycling, drafting is when you cycle closely behind a fellow cyclist (or sometimes vehicle) in order to conserve energy. Due to reduced wind resistance because of the object in front of you, drafting allows you to keep a steady pace while using less power and as such is considered cheating in some races.

Drafting is more commonly seen in pure cycling races as many triathlon races are 'non draft legal'. Additionally, drafting takes skill and precision in order not to cause a crash, which is why most amateur races will not allow drafting while professional races may allow it.

Drafting is most commonly seen in cycling races like the Tour De France and is often banned in amateur triathlon races. 

Duathlon – A duathlon is a race consisting of a run followed by a bike section, followed by a second run. Duathlon is a very popular sport for triathletes to undertake in the winter as open water swimming becomes inappropriate and still allows triathletes to practise their running and cycling in a competitive atmosphere. Duathlon racing is also popular for those who dislike swimming. 

Fartlek – Fartlek is a Swedish term that translates as 'speed play'. Fartlek training is a type of interval training whereby you mix up the intervals to keep your body guessing and make better progress. 

Foot Strike –This is a term that applies to running and refers to the way your foot hits the ground. Different people will have a different foot strike, and most people have either a forefoot strike, mid-foot strike, or heel strike. It's good to know which category you fall into so that you can buy the appropriate running shoes. 

Freestyle – Also known as the “front crawl,” this is the most efficient form of swimming in a triathlon.

FTP – FTP is a cycling term that refers to the average power an athlete can produce over the course of an hour in watts. Many triathletes and cyclists will use a power meter which measures your power output in watts and do a regular FTP test to make sure they are producing a good level of power.  

Half-Ironman – Ironman is a specific brand of triathlon and a half Ironman race consists of a 1.2-mile swim, 56-mile bike, and 13.1 mile run. This is considered a good stepping stone for those who have the goal of completing a full Ironman. Half Ironman is also known as 70.3 due to the number of miles the athlete completes over the course of the race. 

Holding the Line – Holding the Line is a cycling term that refers to cycling in a dead straight line without wobbling or diverging. Holding your line is an important bike skill to have when cycling in groups. 

Indoor Trainer – Also known as a Turbo Trainer, an indoor trainer is a piece of kit that you attach your bike to in order to allow you to ride it indoors while stationary. Many triathletes will use an indoor trainer during winter when conditions don't allow for outdoor cycling. Turbo sessions are notoriously difficult as it can be boring cycling indoors with no scenery and no wind to dry your sweat!

Some turbo trainers will attach straight to the chain ring while others clip onto the wheel. 

Ironman – A full Ironman is considered one of the toughest tests of human endurance and consists of a 2.4-mile swim, 112-mile bike ride, and 26.2-mile run. Completing a full Ironman is the life goal for many triathletes and requires a huge amount of training dedication. 

Long Course Triathlon – A long-course triathlon or full distance triathlon is an unbranded version of a full Ironman.

Mass Swim Start – A mass swim start is when all participants of the triathlon start the swim at the same time. A mass swim start takes some getting used to and it is not uncommon to be kicked or even punched when participating. Practising with a triathlon club can help massively, such as having fellow  members splash you when swimming.

Mdot – The name of the trademarked logo of Ironman. Sometimes when a triathlete has completed an Ironman, they will get the Mdot tattooed on them somewhere as a mark of pride.

Negative Split – If you run a negative split it means that as you progress through the miles, you get faster. 

PR – Stands for “Personal Record.” Also known as a "PB" or "Personal Best". 

Race Number Belt – In triathlon races, you are required to show your race number on your back while cycling but on your front while running. The traditional safety pin method of attaching your race number doesn't allow this, so triathletes will wear a race number belt which fastens the race number securely and can be spun around when necessary. 

Racing Flats – Lighter and “faster” running shoes to be used in races only. These are usually reserved for track running as they are not suitable for running long distances or on uneven terrain. 

RPM – See Cadence.

Swim Wave – If a race doesn't feature a dreaded Mass Swim Start, the swim leg will be divided into waves whereby racers start the swim at staggered times. 

Taper – The period of time before a race where you slow down the frequency and intensity of the workouts in order to give your body time to recover and rest before the event. Most racers will taper for around a week. 

Turbo Trainer– See Indoor Trainer.

Transition – The transition area is the space where you will rack your bike ready for the race. After the swim, you will enter transition in order to collect your bike for the bike leg. Once you've finish the bike leg, you will return to transition to re-rack your bike and head out on the run.

Sometimes there are two different transition areas, usually if the race is point-to-point. For elite athletes, the time spent in transition can mean the difference between a win and not even making the podium, so practising your transition is vital. You will need to practise things like taking off your wetsuit, mounting your bike, and taking on any necessary nutrition. Some athletes spend less than a minute in transition but it is a fine art!

You will enter the transition area before the race to rack your bike and place down any kit you need for later in the race. 

Triathlon Bike – A triathlon bike, or tri bike, is a special type of bike specifically used in triathlon. These do not have conventional handlebars and instead use tri bars as defined above. A triathlon bike can be notoriously difficult to handle so they take some getting used to. Not all races are suited to triathlon bikes as they are better for flat courses and ones that are not too technical. 

VO2 Max – The highest rate at which oxygen can be taken up and utilised during exercise by a person. The higher your VO2 max, the fitter you are and the better at racing you'll be! There are fitness tests you can do to calculate your VO2 max in order to keep an eye on your progress and see how you stack up against others.

Washing Machine – Refers to the swim start in some races where the water is so choppy that it feels like the swimmers are in a washing machine. 

Wetsuit Legal – According to the BTF, wetsuits may be mandatory or forbidden depending on the water temperature. Wetsuits are forbidden above temperatures of 22 degrees Celsius and mandatory when swimming in waters colder than 14 degrees Celsius.