muscle fatigue occurs due to a buildup of
Muscle fatigue Metabolites are the substances (generally waste products) produced as a result of muscular contraction. They include chloride, potassium, lactic acid, ADP, magnesium (Mg2+), reactive oxygen species, and inorganic phosphate. Accumulation of metabolites can directly or indirectly produce metabolic fatigue within muscle fibers through interference with the release of calcium (Ca2+) from the sarcoplasmic reticulum or reduction of the sensitivity of contractile molecules actin and myosin to calcium.
Starvation response Starvation mode is a state in which the body responds to prolonged periods of low energy intake. During short periods of energy abstinence, the human body burns primarily free fatty acids from body fat stores, along with small amounts of muscle tissue to provide required glucose for the brain. After prolonged periods of starvation the body has depleted its body fat and begins to burn primarily lean tissue and muscle as a fuel source.