Sports science definitions and cycle coaching and training terminology

H

Heart Rate Training zones

Classifying the training intensity by heart rate response relative to the physiological landmarks of lactate threshold and maximal aerobic power.

Heart rate variability (HRV)

A measure of the variations in heart rate, usually calculated by analyzing a time series of beat-to-beat intervals from an ECG.

Hypoxemia

Deficiency in the concentration of oxygen in arterial blood. Not to be confused with hypoxia.

Hypoxia

A reduced concentration of dissolved oxygen in the atmosphere. Commonly found at high altitudes.