Learn important terms used in sports medicine and coaching.

40 kilometer TT - A 40 km (24.8-mile) solo race against the clock. Time trials are often referred to as “the race of truth.”

Acute Training Load (ATL) - The overall quantity (i.e., combination of frequency, duration, and intensity) of training that you have performed recently (during the past week or two). See also Chronic Training Load (CTL).

Aliasing - Distortion or artifact in data (such as from a power meter) that occurs when an analog signal is sampled at too low of frequency.

Anaerobic capacity / anaerobic work capacity - The overall quantity of work (not the rate of doing such work, which is power) that you can perform by relying on anaerobic metabolism. Usually trained by performing short (e.g., 30-second to 3-minute), very high-intensity intervals.

Anaerobic threshold (AT) - More correctly termed “ventilatory threshold”; the exercise intensity at which there is a nonlinear increase in ventilation relative to metabolic rate—that is, the rate of oxygen uptake (VO2). Although they are not mechanistically related (i.e., not related as cause and effect), “anaerobic” or ventilatory threshold is often used to estimate lactate threshold.

Average Effective Pedal Force (AEPF) - The average force applied to the pedal that causes the crank to turn.

Big-ring sprint - A maximal effort completed in the largest chain-ring of the bicycle. Usually this large chain-ring is made up of 53 teeth.

BMX (Bicycle Motocross) - A form of bicycle racing in which the competitors ride bicycles with 20-inch to 24-inch wheels and jump over obstacles. They compete against a maximum of seven other riders at a time. The races are very short, usually less than 1 minute.

Cadence - The revolutions per minute (rpm) of the cranks at which you pedal.

Cardiovascular fitness - The capability of the cardiovascular system to transport O2 to tissues (e.g., contracting muscles), aid thermoregulation by increasing blood flow to the skin, and so on. It is traditionally quantified by measuring a person’s maximal oxygen uptake, or VO2max.

CdA - A measure of an object’s aerodynamic drag characteristics. In the context of this book, the object is the cyclist and his or her bike. CdA is the product of the coefficient of drag, Cd, and frontal area, A. Though CdA is best measured in a wind tunnel, it can also be estimated via field tests performed using a power meter.

Chronic Training Load (CTL) - The overall quantity (i.e., combination of frequency, duration, and intensity) of training that you have been performing over a substantial period of time—for example, several months or more. See also Acute Training Load (ATL).

Circumferential Pedal Velocity (CPV) - The speed at which the pedal travels around the circle. CPV determines the speed at which your muscles must contract to produce force and thus power.

Critical Power - Defined in scientific literature as the slope of the work-time relationship. Critical power is an inherent characteristic of the aerobic energy supply system and as such represents a power that can be sustained for a very long time without fatigue. When measured using exercise bouts that are 3 minutes to perhaps 30 minutes in duration, critical power is essentially the same as functional threshold power. See also Mean Maximal Power.

Fartlek - See Tempo.

Fast Find - A feature in CyclingPeaks software that allows the user to easily find specified efforts based on the starting and ending wattage of each effort.

Fatigue Profile - The measure of a cyclist’s resistance to fatigue over Levels 4–7, pinpointing specific areas of weakness when considered alongside the power profile.

Functional threshold power (FTP) - The highest power that a rider can maintain in a quasi–steady state without fatiguing for approximately one hour. When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer.

Intensity Factor (IF) - For any workout or part of a workout, the ratio of the Normalized Power to the rider’s functional threshold power.

Kilocalorie (k/cal) - The amount of energy required to raise 1 kilogram of water by 1 degree Celsius. In common vernacular, 1 kilocalorie is typically referred to as one Calorie (note the capital C).

Kilojoule (kJ) - Like the kilocalorie, the kilojoule is a measure of energy. One joule is equal to 1 watt-second, or the work done by exerting 1 watt of power for 1 second. One kilojoule is therefore equal to 1,000 joules.

Lactate Threshold (LT) - The exercise intensity at which the release of lactate into the blood first begins to exceed its rate of removal, such that blood lactate levels begin to rise. From the perspective of most athletes and coaches, LT is a relatively low intensity, approximately corresponding to the transition between Levels 2 and 3.

Match - A reference to expending a tremendous amount of energy in a short period of time when, for example, attacking during a race. “Burning a match” is when you actually expend the energy.

Maximal Accumulated O2 Deficit (MOAD) - The difference between the rate of oxygen uptake (VO2) and the rate of O2 demand at the onset of supra-maximal (i.e., requiring more than 100 percent of VO2max) exercise continued to fatigue. MAOD is currently considered the “gold standard” for measuring a person’s anaerobic capacity.

Maximal heart rate - The maximal rate at which your heart can beat per minute.

Maximal Lactate Steady State (MLSS) - The highest exercise intensity at which blood lactate levels remain essentially constant over time. MLSS is comparable to functional threshold power and is closer to what most coaches and athletes mistakenly call “LT.”

Maximal neuromuscular power - The maximal power that you can generate under optimal conditions (e.g., at the right cadence).

Mean maximal power - Your highest average power for a particular duration. Referred to by Joe Friel as “critical power.”

Mean Maximal Power (MMP) - Curve The curve of all your average best watts over each second of time, starting from zero seconds and extending to the longest ride you have completed.

Mean Maximal Power (MMP) - Periodic Chart A chart of specific average best power for a certain time period. For example, a line graph of your best 5 seconds for each ride you have completed over the entire year.

Metabolic fitness - The ability of your muscles to balance aerobic energy production with energy demand, which in turns determines the rate of muscle glycogen utilization, blood lactate levels, and so on.

Micro-burst - Intervals with very short work and rest periods (e.g., 15 seconds “on”, 15 seconds “off”). Sometimes also referred to as “micro-intervals.”

Normalized Power (NP) - An estimate of the power that you could have maintained for the same physiological “cost” if your power had been perfectly constant, such as on an ergometer, instead of variable.

Onset of Blood Lactate (OBLA) - The exercise intensity corresponding to a blood lactate concentration of 4 millimoles per liter. An individual’s OBLA is generally close to, but may be significantly higher or lower than, his or her MLSS or FTP.

Overreached - An acute state of fatigue and hence diminished performance resulting from a brief period of excessive training relative to what you normally perform. Although many times riders describe themselves as being “overtrained,” in reality they have usually simply overreached and their performance will recover after just a few days of rest or reduced training.

Overtrained - A chronic state of overreaching from which recovery takes a long period of time.

Performance Manager - Analysis available in WKO+ and other software that allows you to quantify changes in your acute and chronic training load and hence training stress balance over time, thus helping you to build fitness and peak at the appropriate time while minimizing the risk of overtraining, illness, or injury.

Periodic Chart - A chart in CyclingPeaks Software that allows the user to view data over a certain period of time.

Power - The rate of doing work, where work is equal to force times distance.

Power Profile - The specific measurements of power (watts) per kilogram generated at 5 seconds, 1 minute, 5 minutes, and functional threshold power that reveal the relative strengths and weaknesses of a cyclist.

Power Profile table - A table that categorizes the watts per kilogram needed to be successful in each category of racing.

PowerTap - A power meter that measures the torsion in the rear hub of the bicycle wheel.

Preme - A special prize given to the winner of a designated lap in a bike race.

Quadrant Analysis - A graphical means of analyzing data from a power meter to visualize specific demands placed upon the neuromuscular system.

Rate of perceived exertion (RPE) - An individual’s subjective evaluation of how intense or strenuous a particular exercise intensity feels. Typically rated on either a linear 20-point or a nonlinear 10-point scale, both of which were developed by Dr. Gunnar Borg.

Repeatability - The ability of an athlete to repeat a certain effort many times without a loss in power.

Scientifically Computer Aided - Training Era The time that we are now in, in which we are using microcomputers to help us to scientifically apply training principles for peak performance.

Self-selected cadence - The cadence range in which you naturally will pedal without consciously thinking about your cadence.

Small-ring sprint - A maximal effort completed in the smallest inner chain-ring of the bicycle. Usually this small inner chain-ring is composed of 39 to 42 teeth.

Specificity - An important concept of exercise physiology that takes account of the fact that the adaptations to training tend to specific, or unique, to the particular demands that are imposed.

SRM PowerControl - The actual microcomputer that mounts on the bicycle handlebar that comes with the SRM power meter system.

SRM (Schoberer Rad Messtechnik) - Power meter invented by Ulrich Schoberer that measures the torsion in the “spyder” of the right crank arm.

Stochastic - Technically, “varying randomly. ”Often used to refer to the marked fluctuations in power that occur when riding a bicycle outdoors. In fact, such variations are generally not really random but occur because of the ever-changing resistances (e.g., hills, wind) that must be overcome.

Strain gauges - Small foil leaflets that, when incorporated into an electronic circuit and bonded to a surface, can be used to measure the amount of strain, or deformation, occurring in the underlying material. This deformation is related to the magnitude of the force that is applied; hence, strain gauges are used to measure force (or torque).

Sweet spot - A small area of intensity characterized by 88–93 percent of one’s FTP.

Tempo (or “fartlek”) - From Swedish, meaning “speed play”; workouts performed at an intensity that is “up tempo” from what a rider normally trains at when riding at a comfortable level.

Threshold heart rate - The heart rate corresponding to functional threshold power.

Training Stress Score (TSS) - A composite number that takes into account the duration and intensity of a workout to arrive at a single estimate of the overall training load and physiological stress created by that session. It is conceptually modeled after the heart rate–based training impulse (TRIMP).

Variability Index (VI) - The ratio of Normalized Power to average power, Variability Index provides an indicator of just how variable, or “stochastic,” a rider’s power output was during a particular workout.

VO2max - The maximal rate of whole-body oxygen uptake that can be achieved during exercise. VO2max is primarily limited by the ability of the cardiovascular system to deliver O2-carrying blood to exercising muscle; hence, VO2max is considered the best measure of a person’s cardiovascular fitness and sets the upper limit to aerobic power production.

Zero offset - A task that needs to be done when using the SRM and ergomo power meters. For the SRM, it must be done before every ride. For the ergomo, it needs to be done every 600 miles.


Allen, Hunter; Coggan, Andy , PhD (2010-04-01). Training and Racing with a Power Meter, 2nd Ed. (Kindle Locations 6349-6485). Ingram Distribution. Kindle Edition.