CSSD Practice Exam 2026 – Complete Study Resource

Metabolic fatigue is directly linked to the processes occurring during physical exertion when the body relies heavily on anaerobic metabolism. During intense activities, such as sprinting or lifting heavy weights, the body uses anaerobic pathways to produce energy quickly. This process generates lactate as a byproduct, which can accumulate in the muscles and bloodstream.

As lactate levels rise, they can interfere with muscle function and contribute to the sensation of fatigue. This type of fatigue is characterized by a decrease in the muscle's ability to contract effectively due to both the accumulation of lactate and the depletion of energy substrates that are necessary for continued muscle performance.

In contrast, substrate fatigue typically refers to exhaustion of energy sources, chronic fatigue may involve long-term exhaustion often beyond physical exertion, and neurogenic fatigue relates to issues in the nervous system affecting muscle activation rather than metabolic processes. Understanding these differences can clarify how metabolic fatigue specifically arises from anaerobic energy production and lactate accumulation.