Glossary

Aerobic Decoupling: Percentage change in aerobic efficiency between the first and second halves of a session (or portion of session >20 minutes). Generally looking for less than 5% change which means coupled (good) whereas greater than 5% is decoupled (bad).
Aerobic Efficiency: Ratio between Effective Power and Average Heart Rate as measured over the first and second halves of a session (or portion of session >20 minutes).
Anaerobic Work Capacity: Calculated in Joules or Kilojoules, represents the volume of energy available for the anaerobic energy system. The value represents the amount of work that can be done above Critical Power before becoming completely exhausted. The value is determined via Critical Power modeling within the application but can also be managed via Athlete Journal.
Cadence: [Cycling] Measured in RPM (Rotations per Minute), number of pedal revolutions per minute. This is a fundamental component of power and balance metrics.
Core Temperature: Body internal temperature, e.g. temperature of internal organs / blood.
Critical Power: An indication of maximum sustainable power (high intensity) over an extended period of time, e.g. in the range of 30-40 minutes. Typically 5-10% higher than FTP. Used in modeling a hyperbolic power-duration curve to allow for improved insights of an athletes full power profile at differing durations.
Effective Power: Calculated in Watts, Weighted moving average representation of power. Utilized when determining load and intensity.
Empty Tank Effort: Efforts for which w’ balance would be negative i.e. anaerobic work capacity fully utilized.
Functional Threshold Power: Measured in Watts, represents the highest possible power output for an hour. Although classically known as 1 hour power, this is realistically more like the maximum sustained power for 45 minutes to 1 hour. Commonly referred to as FTP.
Fastest Pace: [Running] The best pace for ~1 km or ~1 mile (depending on running units choice) within a session.
Fatigue Resistance: Ability to maintain power output after expending energy.
Fitness Ramp Rate: Rolling average of load, measured by each workouts Training Load.
Flight Time: [Running] Calculated in milliseconds, Amount of time spent off the ground between strides.
Flight Time Ratio: [Running] Calculated in Percent, Ratio of Flight Time to Step Time (i.e. Ground Contact Time + Flight Time) and represents the percentage of stride spent in the air. Generally ranges from 0-50% where 0 is essentially walking. Higher flight time ratios correlate with better running economy.
Form Power: [Running] Measured in Watts, amount of power in vertical motion, not part of power used for horizontal movement. Typically on the order of 90-110% of weight in kilograms.
Form Power Ratio: [Running] Calculated in Percent, ratio of Form Power to Total Power. Values less than 30% are good and less than 28% better. Varies by and depends on terrain.
Grade Adjusted Pace: [Running] An estimate of pace for level ground when running on hilly terrain.
Ground Contact Time: [Running] Measured in milliseconds, Amount of time that one foot is in contact with the ground on each stride.
Heart Rate Reserve: Calculated in BPM (Beats per Minute), the difference between Max Heart Rate and Resting Heart Rate. Gives a better representation of available capacity than just using Max Heart Rate.
Left Right Balance: Measured in Percent, this is the contribution of each leg to power in the pedal stroke, ideal may be 50%/50% but not all athletes are symmetric. Changes in balance over time may indicate fatigue or possible injury onset.
Leg Spring Stiffness: [Running] Measured in Kilo Newtons per metre, represents the stiffness of the muscles and tendons in an athlete’s legs.
Load: Quantification of duration and intensity of a session. Used by training load to determine fitness, fatigue, and form.
Pace: [Running] Measured in minutes per km or mile, the time taken to run a unit distance.
Pedal Smoothness: [Cycling] Represents how consistently power is delivered to the pedal throughout the full pedal stroke. Optional balance metric may not be available with every power meter and may not be available for each leg.
Rate of Perceived Exertion: Scale used to identify exercise intensity via feel (perception) of the effort. Commonly referred to as RPE, the RPE scale runs from 0 to 10.
Resting Heart Rate: Measured in BPM (Beats per Minute), this is the number of heart beats per minute while at rest. Most modern wearables can provide a estimate of this value.
Running Effectiveness: [Running] A calculated metric of the how effective a runner converts power to speed. Relies on athlete weight to perform the calculation.
Segment: A portion of a session, usually a trail, hill, road, or loop that is visited often, for which attempts are tracked and metrics can be compared.
Step Rate: [Running] Measured in SPM (Steps per Minute), number of steps per minute.
Stride Length: [Running] Measured in millimeters, the horizontal distance travelled with each step.
Temperature: Outdoor temperature as measured by a watch or head unit computer.
Torque Effectiveness: [Cycling] Represents how much of the power applied to the pedal stroke in a forward direction. Optional balance metric may not be available with every power meter.
Training Load: The cumulative amount of load placed on an athlete from one or more sessions.
VAM: Measured in metres per hour, represents the speed of elevation gain. Abbreviation for “velocità ascensionale media” or its English counterpart “vertical ascent metres”.
Vertical Oscillation: [Running] Measured in centimetres, the amount of upward movement.
Vertical Ratio: [Running] Calculated in percentage, the ratio of Vertical Oscillation to Stride Length
W’ Balance: Graphical representation of utilizing and recharging anaerobic work capacity throughout a session. Utilizing is time above critical power and recharging is time below critical power.