Fatigue and The Central Nervous System

Fatigue is defined as the inability to maintain a power output or force during repeated muscle contractions (Powers, 2012). The focus of this paper will be to identify the most common types of fatigue and how physical activity affects the level of fatigue on the body. There are two main types of fatigue, central and peripheral. However, these two types are composed of various factors that contribute to fatigue. There are different causes of fatigue, but the origins of fatigue often vary depending on the type of physical activity involved (Powers, 2012).

Central Fatigue is the concept that fatigue originates in the Central Nervous System, also known as CNS. Central fatigue is merely a theory, with evidence both for and against the idea. According to the article by the American Society for Clinical Nutrition, “the inability or unwillingness to generate and maintain central activation of muscle is the most likely explanation of fatigue for most people during normal daily activities.” It was not until recently that it was understood that the Central Nervous System played a part in muscle fatigue (Davis, 2000). There are two concepts that would be necessary to imply that the Central Nervous System plays a role in fatigue; a reduction in the number of functioning motor units involved in the activity or a reduction in motor unit firing frequency would mean the Central Nervous System (Powers, 2012). Physical activity is directly related to fatigue that originates in the Central Nervous System in several ways. For example, exercise begins and ends in the brain. From mentally preparing oneself for exercise to temperature and blood pressure, the body is experiencing fatigue. It is the responsibility of the brain to regulate these factors a...

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