Hardening of the arteries, also called atherosclerosis, occurs when fat, cholesterol, and other substances build up in the walls of arteries. These deposits are called plaques.efinition. Hardening of the arteries, also called atherosclerosis, occurs when fat, cholesterol, and other substances build up in the walls of arteries. These deposits are called plaques. Over time, these plaques can block the arteries and cause problems throughout the body.
CNS fatigue (CNS = central nervous system) is a slightly more convoluted phenomenon, but the term is thrown around frequently in the world of fitness. By itself, the acronym evokes notions of frailty, complication, and extreme caution.NS fatigue (CNS = central nervous system) is a slightly more convoluted phenomenon, but the term is thrown around frequently in the world of fitness. By itself, the acronym evokes notions of frailty, complication, and extreme caution.
The central nervous system (CNS) is responsible for controlling the functions of the body including muscle contractions. There are two origins where the muscles can become fatigued: 1  Localized (in the muscle) also known as peripheral fatigue.2  CNS (at the origin of the muscle contraction) also known as central fatigue.he central nervous system (CNS) is responsible for controlling the functions of the body including muscle contractions. There are two origins where the muscles can become fatigued: 1  Localized (in the muscle) also known as peripheral fatigue.