Short-Term Muscle Disuse Atrophy
Short-Term Muscle Disuse Atrophy

A Novel Amino Acid Composition Ameliorates Short-Term Muscle Disuse Atrophy in Healthy Young Men


When muscles aren’t used, such as during bed rest or limb immobilization, they atrophy, which leads to functional and metabolic decline, and complete recovery is difficult to achieve and slow-coming even with regimented resistance exercise. The majority of muscle loss is due to a decrease in muscle protein synthesis while in a fasted state. To mitigate this decline, nutritional intervention is necessary.

Trial Length

28 days

Number of Subjects




Age Range


The Goal

Essential amino acids (EAAs) have been found to increase muscle protein synthesis and protect against muscle atrophy and weakness in times of illness or bed rest. Researchers examined the effects of EAAs on muscle loss during limb immobilization when combined with the nonessential amino acids (NEAAs) arginine, glutamine, and n-acetylcysteine (NAC).

The Results

For 28 days, 20 young, healthy men received either 10 grams of EAAs plus select NEAAs or a placebo, and for the first 7 days they wore a brace to simulate the effects of unilateral knee immobilization.  

Results showed that the EAAs + NEAAs protected against muscle atrophy and decreased the amount of fat stored.

EAAs + NEAAs protected against muscle atrophy and decreased the amount of fat stored.


The Conclusion

Over a 28-day period that included 7 days of unilateral knee immobilization, supplementation with EAAs plus arginine, glutamine, and NAC, helped preserve quadriceps muscle volume and fiber type specific cross-functional area, and decreased fat accumulation while being safe and well tolerated in healthy young men.

The Why?

Short-term muscle disuse adversely impacts the health and well-being of both young and old adults, including impairing insulin sensitivity and reducing muscle strength. Recovery from muscle atrophy is challenging, even with resistance training, making it all the more worthwhile to target the nutrients, such as amino acids, that can help to protect against the loss of muscle and strength.


Holloway TM, McGlory C, McKellar S, Morgan A, Hamill M, Afeyan R, Comb W, Confer S, Zhao P, Hinton M, Kubassaova O, Chakravarthy MV, Phillips SM,  A novel amino acid compaosition ameliorates short-term muscle disuse atrophy in healthy young men.  Front Nutr 2019; 6:105.  Doi:  10.3389/fnut.2019.00105