The Endurance Glossary

A 10K is a 10-kilometer (6.2 miles) race, exactly twice the length of a 5K.

A 5-kilometer race (3.1 miles), the most common first race.

A 70.3 is a middle-distance triathlon made up of a 1.2-mile swim, a 56-mile bike, and a 13.1-mile run.

A breakaway is a rider or small group that escapes off the front of the main pack and rides ahead on their own.

A trisuit that never rubs on a dry training ride chafes within a few miles of the bike leg, because chafing is the skin injury that repeated rubbing produces at a skin-on-skin or skin-on-fabric interface, and wet fabric more than doubles the friction

A cyclocross race sends riders around a closed circuit of grass, mud and sand, over obstacles that force them off the bike to run carrying it.

Drafting is the act of riding closely behind another cyclist to save energy by staying in the pocket of sheltered air they leave behind.

An echelon is a diagonal line of cyclists that forms when the wind blows across the road instead of straight at the riders.

A half marathon is 13.1 miles, or 21.0975 kilometers, which is exactly half the length of a full marathon.

An Ironman is the full-distance triathlon, a 2.4-mile swim followed by a 112-mile bike and a marathon of 26.2 miles, all raced back to back on the same day.

At around 30 degrees of knee flexion the iliotibial band is pressed against a bony ridge on the outer end of the thigh bone, and IT band syndrome is the pain that compression produces at that point on the outside of the knee.

A marathon covers 26.2 miles, or 42.195 kilometers, and that exact figure has been the standard since the 1908.

An Olympic triathlon covers a 1,500-meter swim, a 40-kilometer bike, and a 10-kilometer run, which works out to roughly a mile in the water, 24.8 miles on the bike, and 6.2 miles on foot.

Rivers, lakes, seas, oceans and channels are the venues that make a swim an open water swim, at any distance from a short lake crossing to the 10 kilometer Olympic marathon.

Overpronation is the name given to the inward roll of the rear foot at the subtalar joint when an observer judges there is too much of it.

Pace is how fast a runner is moving, written as the time it takes to cover a set distance rather than the distance covered in a set time.

A paceline is a group of cyclists riding in a line and taking turns at the front so the work of cutting through the air is shared among them.

In cycling, a peloton is the main group of riders moving together in a road race.

Plantar fasciitis is degenerative irritation of the plantar fascia where its central band anchors to the inner heel, at a point called the medial calcaneal tuberosity.

A slipstream is the pocket of sheltered air directly behind a cyclist as they ride.

A sprint triathlon is the short standard distance in the sport, made up of a 750-meter swim, a 20-kilometer bike, and a 5-kilometer run

A transition in triathlon is the part of the race where an athlete changes from one sport to the next, and the clock keeps running the whole time.

A triathlon is a single race made of three sports done back to back in a fixed order, swimming first, then cycling, then running.

Any running race longer than the 26.2-mile marathon.

A proper VO2 max test involves 8–12 minutes of climbing effort while wearing a mouthpiece and nose clip. It measures the peak rate your body can take in, deliver, and use oxygen, expressed in milliliters per kilogram of body weight per minute.