kestokyky

Kestokyky is a Finnish term that denotes the capacity to endure or sustain performance, load, or function over time. It combines kesto, meaning durability or duration, with kyky, meaning ability or capability. The expression is used across different fields to describe either a person’s endurance or a material’s resistance to wear and fatigue.

In human performance and physiology, kestokyky refers to endurance capacity—the ability to perform work for extended periods. This includes aerobic endurance, muscular endurance, and the capacity to sustain submaximal effort. Assessments of kestokyky in this context often involve endurance tests, recovery dynamics, and measures such as time-to-exhaustion or sustained performance under prolonged activity.

In engineering and materials science, kestokyky describes durability and fatigue resistance of components and structures. It denotes how well a material or system can withstand repeated loading, wear, or environmental exposure without failure. Evaluation relies on fatigue testing, wear resistance measurements, creep assessments, and reliability analyses to estimate service life and performance under expected conditions.

Etymologically, kestokyky is a compound of kesto (durability, duration) and kyky (ability). The term is used in Finnish-language discourse to express a general notion of endurance or durability, with field-specific meanings shaped by the relevant technical vocabulary. See also kestävyys (endurance or sustainability) and related concepts of durability and reliability.