Leucine: A Potential Ergogenic Supplement

Leucine: A Potential Ergogenic Supplement
Review

 
Abstract
Objective: The aim of this systematic review was to research the effects of Leucine on human subjects; in terms of increase in musculoskeletal weight, strength, power output endurance and changes in muscle : fat ratio. Design: Systematic Review. Methods: As part of a BSc Dietetics & Nutrition of the Univeristy of Nicosia, a student performed this systematic review, based on the following steps: 1. Set a list of important questions that had to be answered in order to complete this review with a proper logical explanation of the results. 2. Completed a research through PubMed and ScienceDirect in order to acquire research data, with research criteria including Leucine, muscle, strength, power output, VO2 Max, endurance, fat, mass, human subjects. Results: In literature
Introduction
Leucine is part of the so called BCAAs, one of the three Essential Amino Acids (EAAs), the other Amino Acids (AA) being Isoleucine and Valine, which when put together are called Branched Chain Amino Acids or BCAA’s. As one of the most abundant AA, Leucine has a very important role in various functions in the human body either as a signaling molecule or as a building block of skeletal muscle1. As a signaling molecule Leucine has been shown in a plethora of In-Vivo and In-Vitro studies to elicit Muscle Protein Synthesis (MPS) in skeletal muscle and in adipose tissue via the Mammalian target of Rapamycin ( mTOR)2. MPS signaling pathways within the human body have been shown to be increased in a dose dependent matter with some studies extensively showing that a dose of 3 grams when given orally either as a standalone or in combination with other AAs promoted maximum MPS3. Such benefits in MPS promotion could indicate that Leucine could help in clinical applications with people suffering with muscle wasting diseases like cachexia or sarcopenia and other related diseases4. Other than helping with muscle wasting diseases Leucine has been researched overall as an ergogenic supplement, providing benefits in exercising individuals, with some studies finding that both time to exhaustion increased while recovery time between training has been reduced5.
Leucine structure and where can it be found

Leucine function in the human body
Muscle protein synthesis
Protein breakdown
Check of people on diet, wishing to lose weitht but not muscle mass
Leucine supplementation as an ergogenic aid
L Resistance exercises, muscle strength, power ,hypertrophy
Aerobic exercise (cycling, swimming, running, rowing etc)
Leucine as part of BCAA supplementation
Central fatigue (papers by Watson, P., Maughan, R and others)
Altitude training
Clinical applications
Sarcopenia(old age)
Check for catabolic patholodies (ie cancer, aids etc)

References
1.Nie, C., He, T., Zhang, W., Zhang, G., & Ma, X. (2018). Branched chain amino acids: beyond nutrition metabolism. International journal of molecular sciences, 19(4), 954.
2.Stipanuk, M. H. (2007). Leucine and protein synthesis: mTOR and beyond. Nutrition reviews, 65(3), 122-129.
3.Norton, L. E. (2010). Leucine is a critical factor determining protein quantity and quality of a complete meal to initiate muscle protein synthesis (Doctoral dissertation, University of Illinois at Urbana-Champaign).
4.Moore, D. R. (2014). Keeping older muscle “young” through dietary protein and physical activity. Advances in nutrition, 5(5), 599S-607S.
5.Nelson, A. R., Karagounis, L. G., & Rowlands, D. S. (2015). Leucine-Protein Supplemented Recovery and Exercise. In Branched Chain Amino Acids in Clinical Nutrition (pp. 15-32). Humana Press, New York, NY.
6.