Active Recovery
Though you might be tempted to sit down after your race and not get up for the next 3 days, studies show performing low-intensity exercises immediately after hard activity is better for circulation and helps remove lactic acid.

Anaerobic Threshold
When you exercise above the intensity at which the body's need for oxygen can be met. This intensity can be sustained only briefly. For example, an all-out sprint-which requires a great deal of power output in a short period of time-uses the anaerobic system. Elite endurance athletes on average have a higher AT than untrained individuals.

Bonk
Also known as "hitting the wall," bonking is a state of severe exhaustion. The cause: The depletion of fuel (glycogen) in the muscles because you've failed to eat or drink enough. To avoid bonking, stay fueled with carbohydrates the night before a race, and gels and sports drinks during your event. (For more insider tips like these, pick up the NEW triathlon training book by legendary elite triathlon coach Joe Friel, TheTriathlete's Training Bible. In it, Friel distills his 25 years of experience coaching athletes of all levels into 1,427 must-know tips.)

Brick
A workout consisting

of two disciplines, usually a bike and run. Coaches recommend doing two to three bricks in the few weeks before your race to familiarize yourself mentally and physically with doing two activities back-to-back.

Dolphin Dive
A series of short dives often used by triathletes to get through shore-bound waves into open water. Beginners beware: You may be better off simply swimming under swells rather than dolphin diving, as the maneuver can waste a ton of energy if you're not proficient at the skill.

Lactate Threshold
The exercise intensity at which lactic acid starts to accumulate in your blood stream. This happens when blood lactate is produced faster than it can be removed, which can govern your speed. Exercise helps train your body to process lactate, and stretching also helps increase your threshold by improving circulation.

Total Immersion
A swimming approach based on efficiency. It focuses on four skills: balance, active streamlining, rhythmic weight shifts, and traction.

PR
Personal record.

Negative Split
A technique preached by many coaches in which you pace yourself through the first half of a race in order to run the second half at a faster pace. (Be faster at the end of the race with these 13 Tips from Serious Runners.)

Mashing
The opposite of a "spinner," a masher pedals a big gear slowly to conserve energy, rather than "spinning" a smaller gear at a faster pace. Beware: This technique is linked to knee injuries and leg cramps.

Transition
A place to keep your equipment-your bike, wetsuit, towel, running shoes, and other gear-and to the process of changing disciplines during a race. "Transition 1" refers to a station between the swim and bike portion where you wipe your feet, put on shoes, and mount your bike. "Transition 2" is the checkpoint between the bike and run where bicycles are traded for running shoes. Triathletes consider transition a "fourth discipline" worth practicing before race day to minimize time at the stop.

Cadence
Revolutions per minute, used in reference to both running and cycling. Ideal ranges: 90 to 100 revolutions per minute on the bike; 90 to 100 steps per minute, per foot, while running.

Distance Per Stroke
A freestyle swimming drill where your goal is to take fewer strokes per lap. If it takes you 25 strokes for one lap, you'd want to do the next lap in 23 strokes (without just pushing off the wall farther). Do this by honing in on your form.

Endurance Miles
A cycling workout at a moderate intensity level. You want to stay at a pace below lactate threshold for a majority of the ride.

Intervals
A training method where short bursts of intense effort are interspersed with slower stretches. They help to improve cardiovascular fitness while increasing speed and aerobic power. You can run faster the fun way with these New Speed Routines.

Rating of Perceived Exertion (Borg Scale)
A method of measuring physical activity on a scale of how hard you feel your body is working. The Borg Scale ranges from 6 to 20, with 6 being no exertion at all and 20 being maximum effort. It's believed that the rating you think you are working at can be multiplied by 10 to estimate your heart rate (16x10=160 beats per minute).

Aero Bars
Also can be called "tri bars." They are handlebars that face forward with places to put your elbows. The position keeps your elbows closer to the body and lowers your torso compared to the usual upright biking position. These bars allow triathletes to maintain a comfortable aerodynamic position.

Chamois Butter
A clean, non-greasy lubricant to use for your skin under your biking shorts. In addition to making biking more comfortable, it reduces the chances of saddle sores and restores dried-out chamois and short liners.

140.6
The distance of a full Ironman triathlon. It consists of a 2.4-mile/3.8-kilometer swim, 112-mile/180-kilometer bike, and 26.2-mile/42.2-kilometer run.

70.3
The distance of a half Ironman triathlong. It consists of a 1.2-mile/1.9-kilometer swim, 56-mile/90-kilometer bike, and 13.1-mile/21.1-kilometer run.

Drafting
Tucking in behind someone else during the bike portion of the race so they take most of the wind resistance, giving you an easier ride. The drafting cyclist uses less energy to maintain the same speed as the cyclist in front of them. Because of this, drafting is often illegal in triathlons. (Get the right bike for your budget. Here are the Best Bikesfrom $500 to $5,000.)

Fartlek
Invented by a Swedish coach as a form of interval training to help running speed. You alternate between periods of fast bursts above race and lactate threshold pace and short periods of jogs for recovery. The time of the jog is kept short to keep your body from fully recovering before the next speed burst.

BOP
Back of the pack competitor.

FOP
Front of the pack competitor.

DFL
Dead [expletive] last.

Ladder
An interval workout that progressively increases then decreases distances. For example, run fast for 400 meters, jog for 200 meters, run for 800 meters, jog for 200 meters, and run for 1200 meters. Then work your way back down by running for 800 meters, jogging for 200 meters, running for 400 meters, and finish with jogging for 200 meters.

Century
A 100-mile bike ride.

OWS
Open water swim.

Periodization
Changing the focus and workload of training over a period of time. If you start your training months out, then it's a slow and steady progression to longer and more intense workouts before your body is physically able to compete.

Rabbit
The man or woman you pick out of the race crowd before the race who you will chase and try to pass on your way to the finish. Teams may have a rabbit in place to keep them on a specific pace for a period of the race.

Sprint
The name for a short-distance triathlon. Usually it is a 400-yard swim, 15-mile bike ride, and 3-mile run, though it can vary by race.

Paddles
Worn on the hands during swim training, they increase your workload so you train harder.