base: Also "base pace," refers to a swimmer's pace they can hold for interval sessions. Also defines the lane swimmers choose for masters classes, ie: "John swims in the 1:30 lane." It is also a period of training at the start of your training season.

beach start: When athletes start the swim portion of the race from dry land (not necessarily a beach) and run into the water. 

bilateral breathing: When a swimmer breath on alternating sides.

buoy: The floating markers used on a triathlon course to indicate course layout, distance, and turns. 

circle swim: When a lane of three or more swimmers swim together in a continuous, circle motion, rather than splitting the lane in half (as when driving a car). For example, you might swim to the right-hand side of the lane going in both directions. (TIP: cross the lane as you're making your flip turn so that as you push off you're on the correct side. This will make it easier for those behind you.)

deck: The hard surface around the pool. 

draft: To swim directly behind or just to the side of the swimmer in front of you, which makes it easier to swim. 

drills: Specific swimming exercises a swimmer employs to improve technique and feel for the water.

fins: Rubber "flippers" worn on the feet that, depending on their shape and size, can make swimming easier, change the focus of the kick, or provide propulsion when working on drills.

flags: Small triangular pennants hung over the pool to indicate that the end of the lane is near. Especially important for swimming backstroke so the swimmer doesn't hit the wall.

flip turn: An underwater somersault a swimmer performs at each wall to begin swimming in the other direction. 

floating start: Also "water start." Starting the swim portion of the race from a treading water position in deep water. 

freestyle or front crawl: The common front stroke style usually used in triathlon. 

kickboard: A floating piece of foam used for kicking drills. 

lane: A sectioned area of the pool for lap swimming, can accommodate anywhere from one to 10 swimmers.

lane lines: The floating markers that separate lanes. 

length: From one end of the pool to the other. 

main set: The bulk of a coached swim workout. Usually consists of 2000 to 4000 yards/meters of swimming.

mass start: Common at many IRONMAN events, this is the type of race start where the entire field of athletes begins the swim together, usually 10 to 15 minutes after the pros.

masters: A swim class, group or club for adult swimmers, typically led by a coach.

open water: Swimming outdoors in a lake, river or ocean.

paddles: Pieces of shaped plastic attached to the hand, which increase resistance on the water and thus increase upper-body strength for swimming. 

pull buoy: A floating piece of foam that goes between the legs so that a swimmer doesn’t need to kick. Often used to help the swimmer work on upper body strength. Learn more about pull buoys.

sighting: A technique in which an open-water swimmer lifts their head in order to see where they are going, locate buoys, watch for other swimmers, aim for dry land, etc.

SwimSmart: A program that debuted in 2013, bringing innovation to IRONMAN swims. 

wetsuit legal: A triathlon in which the water is cold enough to allow a wetsuit. For IRONMAN events, this temperature is usually below 76.1 degrees Fahrenheit (24.5 degrees Celcius). 

aerobars: Because it's more comfortable and more aerodynamic for triathlon racing, most triathlon bikes are equipped with a set of bars which attach to the main handlebars (base bars) or stem of a bicycle and allow you to ride in the aero position. These can also be placed on a road bike. 

aero bottle: Many triathletes attach a water bottle to the aerobars rather than to the down tube or seat tube, which makes drinking in the aero position easier. This can also refer to an aerodynamically shaped bottle that is used on the down tube.

aero position: Also known as the time trial position, the aero position involves riding in a "hunched over" position with the elbows resting on the aerobar pads. This saves your running muscles and helps keep you aerodynamic, especially on relatively flat bike courses.

arm warmers: Single sleeves of material worn in cooler weather to shield the arms. Can be removed mid-ride and stuffed in a jersey pocket.

arm coolers: Similar to above, but made of a thinner material intended to keep the arms shielded from the sun in hotter temperatures.

bento box: A small bag that attaches to the top tube of a bike to store food and tools.

bibs: A style of padded cycling shorts that are attached to a bib-like portion that goes up and over the shoulders.

bonk: Because you cover long distances while cycling, it's easy to get stuck during a ride or race without food or calories. When this happens, your blood sugar can drop so low that your brain goes into a fog and your muscles quit firing. This is called a bonk. The fix? Eat fast and eat lots. (See also: "Hitting the wall," below.)

bottom bracket: The central axis on which the bicycle cranks rotate.

brick: A workout consisting of two triathlon disciplines, in which you run immediately after finishing a bike workout or bike immediately after finishing a swim workout.  Multi bricks is where you practice racing so swim to bike to run.

cadence: The speed of pedaling while bicycling, also known as RPM, or Revolutions per Minute. 

carbon fibre: Strong but light material, from which many (top-end) bikes are now made.

cassette: the cassette or cluster is the set of multiple sprockets that attaches to the hub on the rear wheel.

century: 100 mile bike ride.

chamois cream: A cream or lotion that cyclists apply to their crotch area to help ease chafing of the saddle and shorts against the body.

C02 cartridge: A small cartridge of compressed air that enables cyclists to inflate flat tires quickly.

disc wheel: A solid, spokeless wheel that is very aerodynamic and often used as a rear wheel in triathlons. 

down tube: The pat of a bicycle frame that runs from the handlebars and diagonally slopes down towards your back wheel. 

drafting: Riding close enough behind the cyclist(s) in front of you that your pedaling becomes less difficult due to that rider blocking some of the wind resistance. This is illegal in most triathlons; you must typically maintain four to five bike lengths behind the person in front of you. (See the official IRONMAN Rules.)

dropped: When you're riding with a group of cyclists who are drafting, and you eventually get too far behind to be in the draft, you'll find that the gap increases between you and the group, pedaling becomes harder, and you can't catch up. This is called "getting dropped."  

hammer: To pedal very hard, typically for an extended period of time (i.e. "That ride was a Hammer-fest"). 

jersey: A cycling top made of technical fabric, usually equipped with a front zipper for ventilation and back pockets to store food and tools.

kit: The full collection of cycling clothing, often matching and worn together, including shorts, jersey, gloves, socks, vest, jacket, arm warmers, etc.

peloton: The large, main group on a group ride. Not allowed in IRONMAN racing. (See "drafting" above)

power meter: A tool installed on a bike to measure the watts or kilojoules of work a cyclist is producing.

seat post: The tube on the bike that attaches to your saddle and is typically adjustable. On some triathlon bikes, it can be cut. 

spin: To ride easy or pedal with very low resistance. (i.e. "We went for an easy spin.")  

time trial: Typically a 20-180K ride at the maximum sustainable pace, usually performed in the aero position. The bike leg of most triathlons is defined as a time trial. 

top tube: The tube that extends from the handlebars, between your legs, and horizontally back towards the back wheel. 

trainer: The nickname given to a stationary trainer, where indoor cycling or specific intervals can be easily completed. (i.e: "I did a killer trainer workout last night.")

tri bike: A nickname for a time trial bike, or aero bike, commonly used in triathlon. A lightweight bike with specific bar and seat post set-ups, as well as weight modifications, for riding in the aero position. 

tube: The rubber inner tube that goes inside a bicycle tire. 

tubeless tires: Bicycle tires that do not have a separate tube that goes inside.

watts: The amount of power, in watts, an athlete is generating on the bike. Measured by a power meter.

5K: 3.1 mile run or race. Generally the distance in a sprint triathlon.  

10K: 6.2 mile run or race. Generally the distance in an Olympic triathlon. 

aerobic: This term is used to define the intensity of a run that is primarily conversational at a slow, easy pace. Generally, you burn more fat as a fuel and produce less "painful" lactic acid. 

anaerobic: High-intensity pace that allows lactic acid to build up, and can generally not be sustained much longer than a 10K. 

elastic laces: The "stretchy" shoelaces many triathletes have on their shoes to allow easy and fast entry into the shoe without having to tie a knot. 

fartlek: A style of running that is "random" or variably paced. For example, a fartlek run might involve running five miles on a trail, and sprinting at various intervals throughout the run. Also known as "speed play."  

hill repeats: When a runner runs up a hill to increase their strength, and down at an easy, recovery pace. Also used in cycling. 

hitting the wall: Generally happens about mile 20 of a marathon due to depletion of carbohydrate. A drop in blood sugar leads to immediate fatigue and loss of energy. (Also called a "bonk.")

intervals: Short, fast repeats of 30 seconds to five minutes, interspersed with easy walking or jogging in between each effort. 

MAF (Maximum Aerobic Function): A heart rate training zone developed by Phil Maffetone.

marathon: 26.2 miles. Generally the distance in an IRONMAN triathlon (a half-marathon is the distance in an IRONMAN 70.3 event.) 

negative split: Running the second half of a run faster than the first half.

pick-ups: Short accelerations performed during the run, generally to stretch out the legs and prepare them for speed work or a run. Usually 10-30 seconds long. 

plyometrics: Jumping, bounding, hopping or other explosive movements designed to train the body for reducing ground contact time. 

pronation: The inward roll of the foot as the arch collapses after the foot strikes the ground. Over pronation is excessive inward rolling due to weak support, which can cause many running injuries. 

runner’s high: An intense feeling of exhilaration that can occur during a run, usually due to the release of endorphins. 

splits: in running, refers to your times at mile markers or other pre-planned distance markers.

strides: Similar to pick-ups, but usually performed as intervals (i.e. a set of 8 strides to warm up prior to a race). 

supination: Opposite of pronation. Outward rolling of the foot after foot strike. Less common, but also a cause of running injuries. 

tempo runs: Sustained effort training runs, usually 20 to 30 minutes in length, at 10 to 15 seconds per mile slower than 10K race pace.  

AG or Age Grouper: Amateur athletes are called age-group athletes, competing with others in 5-year age and gender groups. Race age is determined by one’s age on Dec. 31 of the race year.

aquabike: A race comprised of a swimming stage followed by a bike stage with no run.

aquathlon: A swimming stage followed by a run stage with no cycling stage.

ATP: Annual Training Plan

big gear: It's using the bigger gear on your front chainring on your bike, making the workout harder at the same cadence. It is also used to create more power and speed on flatter roads.

body marking: Race number on arm and age on calf with temporary tattoo or black marker.

BOP: Back of Pack

Borg Scale: A method of measuring physical activity on a scale of perceived exertion or how hard you feel your body is working. (See also RPE.)

BPM (beats per minute): A measure of heart rate.

BMR: Basal Metabolic Rate which is better way for athletes to gauge their calorific needs.

BTF (British Triathlon Federation): The national governing body for triathlon in Great Britain. BTF members comprise Triathlon England, triathlon Scotland and Welsh Triathlon.

burnout: Condition like overtraining, caused by doing too much and/or too soon and/or with too little rest.

Cassette: The set of cogs at the rear wheel hub. Used for gearing.

Circuit resistance training: A circuit of various weights to be completed one or more times with minimal rest between exercises. The emphasis is on endurance rather than power or strength.

Clip-in pedals: Designed to securely accommodate special cycling shoes, meaning your feet sit in the most efficient position to transmit power through the pedals.

Cooldown: Physical activity done after a workout or competition to loosen muscles and rid the body of lactic acid.

Cross-train: To engage in various sports or exercises especially for well-rounded health and muscular development.

Criterium: Short-course road races with multiple corners taken at high speeds in a pack riding situation.

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

Chainsuck: The chain fails to disengage from the bottom teeth of a front chain ring; instead the teeth snag the chain and carry it up and around the rear circumference of the ring, winding it back onto itself, and jamming it between the chain-rings and chain-stay.

Chamois cream / butter: A clean, non-greasy lubricant between you and your cycling shorts. In addition to making biking more comfortable, it reduces the chances of saddle sores, and restores dried-out chamois & short liners.

Cleats: Attached to the bottom of your bike shoes, allowing them to lock into clipless pedals.

Clincher wheels: Regular bike wheels. Compare to tubular wheels. 

Derailleur: A system of variable-ratio gears allowing you to adjust a bike’s gearing and thus your cadence.

Dismount line: Where you dismount from your bike – do it before the line!

Dolphin Dive: A technique used to get through shallow water involving doing short, shallow dives until you are deep enough to swim

Drafting: The practice of tucking in behind someone else so they take the brunt of the resistance and you get an easier run/swim/bike, sometimes explicitly prohibited in races. Also known as slipstreaming.

DNF: Did not Finish.

Drills: Repetitive exercises focusing on technique to promote efficiency.

Duathlon: A run-bike-run race (no swim section as in a triathlon).

DQ: Disqualified.

Fingertip drag: Time-honoured swimming drill used to promote freestyle arm efficiency.

Frame size: Common bike measurement, traditionally taken from the middle of the bottom bracket to the top of the seat tube. It’s vital your bike is the right fit as your seating position will affect efficiency, comfort and drag.

Gels: gels are gooey liquid in a pouch which can help replenish your glycogen stores.

Half IRONMAN or 70.3: 1.2 mile/1.9K swim; 56 mile/90K cycle; 13.1 mile/21K run.

HRV (Heart Rate Variability): This is a way of determining your stress levels - physical and mental. It's a way to help avoid over training.

Hybrid: A bike somewhere between a mountain bike and a road bike. Good for all-round use.

IM or IRONMAN: Ironman distance (2.4-mile/3.8K swim, 112-mile/180K bike, 26.2-mile/42.2K run)

Lactate Threshold: The highest level at which your muscles can still convert glycogen to glucose aerobically (i.e. using oxygen). Exercising above this level will soon lead to discomfort as lactic acid (a by-product of the anaerobic process) accumulates in the bloodstream. Training at, or slightly above, this threshold will gradually push it upwards, allowing you to race faster. Also known as Anaerobic Threshold (AT)

Long, slow distance training (LSD): Exactly what the name implies – essential cardiovascular training foundation for endurance events.

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

M. or M dot: Abbreviation of Ironman, often used in online chat forums.

Mantra: A phrase your use to motivate yourself during training or a race.

Marathon: A 26.2-mile running race, which constitutes the third part of an Ironman

Mashing: A cycling term indicating pedalling a big gear (53 x 13 or 14) with a slower cadence instead of spinning a smaller gear.

Maximum heart rate (MHR): The maximum rate that your heart can achieve. A rough rule of thumb is 220 minus your age.

Mount line: You can’t get on your bike until you cross this line.

Multisport: A sport consisting of more than one discipline, including triathlon, duathlon, aquathlon, aquabike, off-road triathlon and winter triathlon.

MTB: Mountain Bike

Number Belt: an elastic belt worn during the bike and run which you put your number on. It makes it easier to switch your number from your back on the bike to your front on the run. It may also have room for gels.

Off-road triathlon: An open water swim, mountain bike ride, trail run combination race. 

Offseason: The time after competition season and before preseason. Can be used as a time to recover or work on new skills.

Olympic or Standard Distance Triathlon: 1.5K swim; 40K cycle; 10K run.

Over training syndrome: Overtraining syndrome is the result of overtraining! It is a neuroendocrine disorder (meaning it affects nerves and hormones). It has sometimes previously been termed ‘burnout’ and ‘staleness’. 

OWS: Open Water Swim, for example in the sea or a lake as opposed to in a pool.

PB: Personal Best

Periodisation: Carefully planned training schedule, focusing on different training elements in turn and culminating with a specific competitive goal.

PR: Personal Record

Pull – Take a pull: Taking a turn to lead, allowing those behind to draft you and follow your pace.

QR: Quick release lever that allows bike wheels to be easily removed and replaced for travel.

Racking your bike: Placing your bike in the transition area on provided racks.

RED-S: Relative energy deficiency in sport (RED-S) is the result of insufficient caloric intake and/or excessive energy expenditure.

RPE (Rate of Perceived Exertion): Means of evaluating how hard you are working, using either a scale of 1-11 or 1-21. The higher the number, the harder you are working. Considered by some to be more useful than measuring heart rate alone.

Rider position: Wind resistance makes a big difference in the bike leg so make sure you are leaning forward and slicing through the air rather than sitting up like a giant sail.

RPM: Revolutions per Minute which refers to the turning of your legs on the bike and how many turns you can do in 60 seconds.

Run or Ride Belt: Waist-mounted belt for carrying snack bars/gels/drinks.

Slick tyres: Thinner and faster road tyres, favoured by those looking for quicker times.

Sprint: A short-distance triathlon. Approximately 400-yard swim or 750m swim, 20km or 15-mile bike, 5km or 3-mile run.

SPD clips: Shimano Pedalling Dynamics clipless pedal system (now a standard term).

Sweat test: A great test to do to workout your sweat rate so you know what hydration you need on race day.

T1 or Transition 1: First transition, where a competitor switches from the swimming stage to the cycling stage.

T2 or Transition 2: First transition, where a competitor switches from the swimming stage to the cycling stage.

Taper: 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.

Tempo Training: Working just below your lactate threshold for an extended period (rather than a short interval). This will raise the threshold, raising the speed at which you can run for long periods.

Timing chip: You’ll wear a chip, attached to an ankle strap, through the whole race to track your time.

Time-trial or TT bike: A serious (and often expensive) racing bike for competitive triathletes.

Toe Clips: A clip on a bike pedal that ensures the foot doesn’t sit too far forward. 

Transition area: The area where the change is made from one sport to the next. It’s important to be able to quickly and efficiently locate your own equipment, and the process of switching sports should be practised to avoid losing hard-earned time.

Training Camp: A break away, usually to a warm climate, where you concentrate on training without distration.

Trisuit: These are shorts and a top, or a one-piece style, that you wear through the entire race.

Tri bike: Bike specifically designed to be ridden in an aerodynamic crouched position, with a high saddle and low crossbar.

TT (Time Trial): A timed session used for reference when recording progress with your training. Usually used in reference to a cycling event but can be used for swimming and cycling benchmarks. For running you may do a Cooper Test.

Turbo (static or indoor) trainer: A device that holds a bicycle in place, applying resistance to the rear wheel. Used for indoor training and brands include Wahoo, Elite and TACX.

Unilateral training: an effective way to improve balance and core strength.

Wall, the: The sudden feeling of physical and/or mental fatigue as the body runs out of glycogen and switches to burning fat stores for energy instead.

Warm-up: To engage in activity before a race or workout. Warming up has a wide range of physiological and psychological benefits. Read about the benefits of a warm-up.

Water Running: An low impact alternative to running if you are injured or need a break from running.

Waves: When a race starts in staggered groups (waves) usually separated by gender and age groups.

Wetsuit: A close-fitting suit made of rubber and worn by swimmers when they are in cold water to keep their bodies warm. Wetsuits also make you more buoyant and faster.

Wetsuit compulsory: Where the race director determines that the use of a wetsuit during the swim leg of the race is compulsory, because of the low water temperature.

Non-wetsuit swim: Where the race director determines that the use of a wetsuit during the swim leg of the race is not permitted, because the water temperature is too high.

WTC (World Triathlon Corporation): The owners of the Ironman trademark.

World Triathlon: World Triathlon, previously known as the International Triathlon Union (ITU), is the international governing body for the multi-sport disciplines of triathlon, duathlon, aquathlon and other nonstandard variations.