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Definitions of words, phrases, and acronyms commonly associated with triathlon and other multisport competitions.


Aero Bars: Extensions to the handlebars of a bike designed to reduce air resistance. On a triathlon specific bike (see ‘Tri-bike’), two extensions often include shift levers at their ends. On a road bike (see ‘Road bike’), the extension is often a single piece unit. The shift levers are on the ends of the handlebar.

Aero Position: A position used in riding a bike in which the rider leans forward and down to reduce air resistance. In most bikes used for triathlon, the bikes design encourages the rider into this position because it is the most comfortable.

Aerobic Training: Exercise, such as walking and jogging, that increases heart rate moderately and uses oxygen to produce energy. Compare with ‘Anaerobic Training’.

Age Group: Competition for awards between those of a similar age range and gender. An example of an age group is men ages 65 through 69.

Anaerobic Training: Exercise, such as sprinting, at heart rates greater than the aerobic zone that uses glucose, in the form of glycogen, stored in your muscles for energy. Compare with ‘Aerobic Training’.

Aquabike: A multisport race format consisting of only the swim and bike legs.

Athena: A USA Triathlon (USAT) competition category for female athletes who weigh at least 165 pounds (75 kilograms), independent of their age.


Biathlon: A multisport race format consisting of only a single bike and run leg. A similar format is duathlon, which includes a run-bike-run sequence.

Bike Leg: The second segment of a traditional triathlon, during which participants cycle a specified distance.

Body marking: A pre-race activity involving writing using an indelible marker or applying a temporary tattoo with the race number of a participant to parts of the body, such as a shoulder and calf. This allows race officials to identify a participant during the race. The location and number of marks varies among races. For some competitions, the participant’s age is written on the opposite calf.

Brick Workout: Training session that combines two disciplines, typically bike and run.


Cadence: The rate at which a cyclist pedals, measured in revolutions per minute (RPM)

Clip-in Pedals: Bike pedals that attach to special cycling shoes, improving efficiency.

Clydesdale: A USA Triathlon (USAT) competition category for men who weigh more than 220 pounds (100 kilograms), independent of their age.


DNF (Did Not Finish): A participant who started but did not complete the race.

DNS (Did Not Start): A participant who registered but did not start the race.

Dolphin Dive: A technique used to enter shallow water efficiently during the swim.

Drafting: Riding closely behind another cyclist to reduce wind resistance.

Duathlon: A multisport race format consisting of a run-bike-run sequence. There is no swimming or kayaking in this competition.


Fueling: Consuming energy gels, bars, and fluids during the race for sustained energy.


Gels: Packets of semi-liquid (like thick, hot fudge without the heat) or semi-solid (like gummy bears) material made with quickly absorbed and metabolized sugars to give a racer extra energy.


Half Ironman® triathlon: A triathlon format typically comprising a 1.2 mile (1.9 km) swim, 56 mile (90 km) bike, and 13.1 mile (19.1 km) run. Sometimes referred to as either half iron distance or Ironman 70.3, because the sum of the three distances is 70.3 miles.

Hill repeats: A run training workout that involves several repetitions of a sprint up a hill followed by walking or jogging back down.

Hybrid bike: A design that uses features of both road and mountain bikes for a bike suitable for general-purpose riding over various types of terrain. The hybrid bike’s flat handlebar allows for a more upright riding position, favoring comfort over speed.


In water start: A format of the start of a triathlon or multisport competition that begins with a swim in which participants begin from a position within the body of open water. This format is often used when running into the water could result in injury because of the nature of the bottom, such as being slippery.

International triathlon: A triathlon format typically comprising a 1.5 km swim, 40 km bike, and 10 km run.

Interval Training: Alternating periods of high and low-intensity training. This training format encompasses High Intensity Interval Training, or HIIT, and Tabata.

IRONMAN® triathlon: A triathlon format typically comprising a 2.4 mile (3.8 km) swim, 112 mile (180 km) bike, and 26.2 mike (38.2 km) run. Sometimes referred to as either full iron distance or IRONMAN 140.6, because the sum of the three distances is 140.6 miles.

IRONMAN® 70.3: See ‘Half IRONMAN’ definition.


Olympic Triathlon: See ‘International triathlon’ definition.

Open Water Swim: Swimming in natural bodies of water like lakes, rivers, or oceans.

Out and Back: Layout of the course for a leg of a triathlon in which the path to the mid-point turnaround is the same as from the turnaround to the finish of the leg, such as swim exit, bike dismount line, or run finish line.


Pacing: Managing energy output to ensure endurance throughout the race.


Race Belt: Elastic belt worn during the run with attached race number.

Race officials: Persons on the race course who ensure rules are followed.

Recovery: A process that helps athletes heal physically and mentally as quickly as possible after training and competition. Activities that may be part of the process are low intensity exercise, such as walking or easy swimming; getting extra sleep; massage; and eating and drinking anti-inflammatory foods and liquids.

Repeats: A format of exercise or training that makes use of several (typically five to ten) short periods of high speed swimming, biking, or running followed by a period of recovery.

Reverse Triathlon: A triathlon format in which the order of the three legs is performed in reverse order, that is, run-bike-swim.

Road Bike: A design focused on speed and maneuverability for long distances on a wide variety of terrains. The road bike is characterized by bent or dropped handlebar ends that promote a more aerodynamic position than when sitting upright.

Run Leg: The final segment of a triathlon where participants run a specified distance.


Split: Time recorded for each of the legs of a triathlon or other multisport race, including for the transitions between the legs.

Sprint triathlon: A triathlon format typically comprising a 0.25 to 0.5 mile (400 to 800 meter) swim, 12 to 15 mile (19 to 24 km) bike, and 3.1 mile (5 km) run.

Super-sprint triathlon: A triathlon format typically comprising distances half those for the sprint triathlon.

Swim leg: The first segment of a triathlon where participants swim a specified distance.

Swim wave: A group of participants who start the swim leg of a triathlon at the same time.

SWOLF: A word formed by combining ‘swimming’ and ‘golf’ to provide a measure of swimming efficiency. As with golf, a lower swolf is better in that it indicates a more efficient stroke.


Time trial start: A format for starting a triathlon whereby participants begin one at a time, typically five to ten seconds apart.

Time trial bike: Like the triathlon bike, this design focuses on aerodynamic efficiency. However, the triathlon bike gives some efficiency in favor of comfort for rides of several hours required for longer triathlon distances.

Transition 1 (T1): The transition from swim to bike in a triathlon performed in standard order.

Transition 2 (T2): The transition from bike to run in a triathlon performed in standard order.

Transition area: The designated area where participants switch between different legs of the race.

Transition mat: A small mat placed in the transition area, typically beside their bike, for athletes to stand on while changing shoes.

Transition rack: The structure where bikes are placed in the transition area.

Transition time: The time it takes to switch between disciplines in a race.

Triathlon bike: A design aimed at placing the rider in an aerodynamic position to reduce air resistance. Triathlon bikes are primarily designed for speed in a straight line, though are also capable to cornering and climbing.

Tri-bike: See ‘Triathlon bike’.

Tri-suit: A one-piece garment worn by triathletes designed for use in the three legs of a triathlon or all legs of another multisport race format.

Triathlete: An individual who competes in triathlons.

Triathlon: A multisport race consisting of swimming, biking, and running segments (legs).


USA Triathlon: Abbreviated USAT, it is the national governing body for triathlon, duathlon, aquathlon, aquabike, winter triathlon, off-road triathlon and paratriathlon in the United States. USA Triathlon is a member federation of the U.S. Olympic & Paralympic Committee and the World Triathlon. Source: https://www.usatriathlon.org/about.


Wave: see ‘Swim Wave’.

Wetsuit: Neoprene garment worn during the swim to provide buoyancy and insulation. The material of triathlon wetsuits is thinner than that used in wetsuits used for surfing or diving. This is because a triathlon wetsuit must be more flexible to provide full range of motion for swimming long distance.

® IRONMAN and IRONMAN 70.3 are registered trademarks of World Triathlon Corporation. 

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