A relative measure of the amount of effort one is putting into a workout respective of that individual’s maximum capacity but irrespective of the total time of the workout. i.e. High Intensity means operating at a pace, effort, or power level close to one’s maximum regardless of how much time (volume) is spent at that level. 

A specific distance or period of time during a workout when a certain pace or effort level is maintained.  e.g. a 5k run workout broken up into 3 1k intervals at maximum effort and 2 1k recovery intervals. 

A triathlon consisting of the following distances 2.4 mile swim/112 mile bike/26.2 mile run.