Strain is a summary metric of the strain undergone by the cardiovascular system during an individual Activity or over the course of a day. It is shown on a scale from 0 to 21.
All out workouts are 18 and above; strenuous workouts are typically 14-18; moderate workouts are typically 10-14; and everything below 10 represents degrees of light or minimal activity. The same scale applies to your entire Day’s Strain.
An activity’s Strain is a measure of how hard you worked, not what you did; as a result, different individuals will not necessarily receive identical scores for completing identical workouts. For example, a “very hard” workout for you may be a “near maximal” workout for someone else.
To learn more about Strain listen to Podcast No. 26: Understanding Strain