Mitigation of Muscle Loss in Stressed Physiology: Military Relevance
Amino acids are the building blocks of the protein that makes up hair, skin, bones, nails, and muscles and gives shape and function to our organs. Muscles act as a reservoir of these amino acids, and when the body is exposed to extreme stressors it turns to the muscles for the essential amino acids it needs to properly function. As a consequence, muscle mass and strength become severely depleted, which impairs exercise capacity and increases the risk for disease and all-cause mortality, and lowers quality of life.
The effects of stressors on muscle health in otherwise healthy individuals can be aptly demonstrated in military personnel during training and combat. Understanding these effects can help in the formulation and application of nutritional strategies to help maintain muscle mass and function in times of severe illness or stress.
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In this review, researchers examined previous studies on potential treatments for muscle loss during critical care and illness, such as that which occurs in severe burn victims, to determine strategies for managing muscle loss due to external stressors during military operations.
In times of extreme stress, the body is unable to build as much muscle. Its anabolic capabilities are blunted. The figure below demonstrates this process as it applies to military personnel.
The analysis revealed that restoring normal testosterone levels during prolonged periods of operational stress can help support the muscle-building effects of dietary protein on muscle. Restoring hormonal balance improves protein synthesis (the creation of new protein) and protects the muscles against amino acid depletion.
Optimal protein intake, such as from a dietary supplement of essential amino acids, helps protect against muscle protein breakdown and boost muscle protein synthesis, thereby benefiting the performance of military personnel in times of stress.
Based on the positive influence of restoring normal hormonal signaling and optimal protein and essential amino acid intake on muscle’s response to nutrition/protein, researchers advocate for conducting more studies that determine the optimal intake and profile of essential amino acids during times of physiological stress.
Establishing effective interventions to improve muscle net protein balance in military personnel is important for maximal performance. In addition, optimizing nutritional support for military operations can also help establish targeted nutritional supplements for otherwise healthy individuals going through times of stress or illness. Essential amino acids show the most promise as a targeted therapeutic for maintaining muscle mass, strength, and function during exposure to external stressors.
Church DD, Gwin JA, Wolfe RR, Pasiakos SM, Ferrando AA. Mitigation of muscle loss in stressed physiology: military relevance. Nutrients 2019 Jul 24; 11(8). Pii: E1703. PMID: 31344809: PMCID: PMC6724061; DOI: 10.3390/nu11081703