Triathlon 101

When first starting out doing triathlons, I was unaware of the unique language triathletes used. Fartlek, 70.3 and brick suddenly became part of my everyday vocabulary. We've tried to highlight the most common triathlon terms below to help you decode triathlon speak.


Half Ironman distance (1.2mi/1.9km swim, 56mi/90km bike, 13.1mi/21.1km run)


Ironman distance (2.4mi/3.8km swim, 112mi/180km bike, 26.2mi/42.2km run)

1/2 IM

Half Ironman (1.2mi/1.9km swim, 56mi/90km bike, 13.1mi/21.1km run)


6.2 miles

2 a day

Two workouts per day


3.1 miles

Aero Bars

Bars that are used to help triathletes maintain a more comfortable aerodynamic position. These forward-facing handlebars allow triathletes to place their elbows comfortably. Sometimes shifters are included.

Aerobic Exercise

Aerobic exercise refers to any type of exercise performed at a moderate intensity level for an extended length of time while maintaining an increased heart rate.

Age Grouper

A non-professional triathlete who competes in their own age category.


Average Heart Rate

Anaerobic Exercise

Anaerobic exercise refers to a short burst of intense exercise such as sprinting or jumping. This is the initial phase of exercise where glycogen or sugar is consumed without oxygen, which is a far less efficient process.

Anaerobic Threshold

At this exercise intensity, lactate (lactic acid) starts producing more quickly than it can be removed (metabolized), causing it to accumulate in the blood stream.


Anaerobic Threshold


Annual Training Plan

Basal Metabolic Rate

The BMR is the amount of energy that is used during rest when in a neutrally temperate environment. The digestive system is inactive during this post-absorptive state. When inactive, approximately 12 hours of fasting is required.

Big Gear

Use the big gear at the front of your bike for a more challenging workout.

Bike Porn

The photos your friends share of their brand new bikes.


This can happen when glycogen stores in the liver and muscles are depleted. If experienced, fatigue will set in and you will notice a significant performance drop because of sudden energy loss.


Beats per Minute (referring to heart rate)


This is a combination workout that includes running and biking. Triathletes joke that “brick” stands for “bike/run it can kill” or “bike/run ick”.


The number of RPM's when you are on your bike.


Did not finish


Did not race


Did not start

Dolphin Dive

This technique is used to get through shallow water more easily. It involves doing short shallow dives, standing, and then repeating until you're deep enough to swim.

Dolphin Kick

Swimming face down and kicking your legs together as one, used with the butterfly stroke.




This is when one athlete follows another at the same speed. The second athlete, who is drafting, gains an advantage (about 20%) since he is doing less work. In triathlons, drafting is usually illegal on the bike and legal for the swim. Drafting is always legal in world cup triathlon events and the Olympics.


A race consisting of running, biking, and then running again.


This Swedish term means “speed play” and describes a relaxed version of interval training.


Heart Rate


Heart Rate Monitor


Individual Medley. In swimming this consists of four strokes of equal distance, usually between 100 and 400 yards. The medley includes butterfly, backstroke, breast stroke, and then any stroke except the first three, likely freestyle.


Ironman distance (2.4mi/3.8km swim, 112mi/180km bike, 26.2mi/42.2km run)

Interval Training

This type of training involves cardiovascular exercise and alternating between brief near-maximum exertion and periods of lower-intensity work. Examples include biking, running, and rowing.

Lactate Threshold

This is the highest exercise intensity you can go for an extended period before lactic acid starts accumulating in the blood stream.

Lactic Acid

Working muscles use lactic acid for energy. The muscle cells convert glucose into lactic acid, and then it is absorbed and converted to a fuel by mitochondria in muscle cells. Lactic acid is responsible for causing muscle soreness.


This is an interval workout where you gradually increase the distance at each interval. Once you reach the greatest distance, you gradually decrease the distance at each interval. For example: run for 400m, jog for 200m, run for 800m, jog for 200m, run for 1200m, jog for 200m, run for 800m, jog for 200m, run for 400m, jog for 200m.


In cycling, this term indicates pedaling a big gear with a slower cadence as opposed to spinning a smaller gear.


Ironman trademark that many people get tattooed on their bodies after completing a full Ironman


Maximum Heart Rate


Main set of a workout.

Negative split

This is when you complete the second half of a workout or race faster than the first half.


Olympic distance triathlon (1.5K swim, 40K bike and 10K run)


Open Water Swim


Personal best


This term refers to the main group of riders biking together in a road bicycle race.


This is a training plan where the training levels vary over distinct periods of time in order to prevent overtraining.


Personal record

Race Packet

This is the packet you retrieve that includes your race number, swim cap, chip, etc.


Race Director


Resting Heart Rate


Rest interval


Rest, Ice, Compress, Elevate. What you should do if you get hurt during training.


Revolutions per minute. This is the rotation speed, so in cycling, this refers to the pace at which you are pedaling.


When your race or workout is divided into parts, this is your time for one part. For example, in a 5k run, the mile splits are your times for each individual mile.


This is a short distance triathlon (400 yard swim, 15 mile bike, and 3 mile run).


Transition 1 is the transition area during a triathlon between swim and bike.


Transition 2 is the transition area during a triathlon between bike and run.

Transition Area

There is a designated area where athletes can keep their belongings during a triathlon. It's part of the race course. Bikes, wetsuits, and running shoes are kept in these transition areas so athletes can switch events quick and effectively.

Transition Run

A short run off the bike that lasts about 10 minutes or one mile. This is different from a Brick, which is a longer run.


This is a bike specifically designed for triathlons, allowing cyclists to ride in the aerodynamic position. They are light weight, and also include aero bars and a steep seat tube angle for optimal results.


This is a special breed of triathlete. They show up to registration with their aero helmet on. They comment on how much better their bikes are. They aren't there just to enjoy the event and have a good time and often look down at normal triathletes that can't spend 30 hours a week training. 


This term is used to describe someone who is obsessed with triathlons and all things associated with it.


Time Trial (usually in reference to cycling)

VO2 Max

This is the highest rate a person can take in and utilize oxygen during exercise.


Some races start in waves, as opposed to en masse. Triathletes are split into waves, separated by gender and age.


World Triathlon Corp, owners of Ironman trademark

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