Skeletal Muscle Response to Amino Acids and Load Carriage Exercise

Skeletal Muscle and Physical Performance Responses to Leucine-Enriched Nutrition Supplementation During Load Carriage

Warfighters often experience physical overload, as the uniform and associated gear that they carry burdens them with substantial loads. The loads increase energy expenditure to levels that exceed a Warfighter's typical energy intake. The typical assault load is approximately 25 kg, although loads as high as 55 kg are often carried, which when combined with extreme energy expenditures can degrade health and performance, and increase the risk of injury. Branched-chain amino acid (leucine) supplementation may confer protection against the negative effects of operational stress by stimulating muscle protein synthesis and reducing degradation. This study will determine if leucine-enriched nutrition supplementation confers protection against the negative consequences of sustained load carriage exercise, and explore the mechanisms by which leucine might impart protection.

Study Overview

• Status: Completed
• Conditions: Muscle Loss; Muscle Anabolism; Muscle Performance
• Intervention / Treatment: Other: Placebo; Other: Leucine-enriched nutritional supplement

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Natick, Massachusetts, United States, 01760
      • US Army Research Institute of Environmental Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 39 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Weight stable (±5 lbs)with a body mass index between 22-29 kg/m2 and a VO2peak of 40 - 60 ml/kg/min
• Willing to refrain from taking any NSAIDS (i.e., aspirin, Advil®, Aleve®, Naprosyn®), or any aspirin-containing products, alchohol, and nicotine
• Females must be on oral contraception

Exclusion Criteria:

• Metabolic or cardiovascular abnormalities, gastrointestinal disorders
• Disease or medication that affects macronutrient metabolism or the ability to participate in strenuous exercise
• Allergies or intolerance to foods (e.g. lactose intolerance/milk allergy), vegetarian practices, or medications (including, but not limited to, lidocaine or phenylalanine) to be used in the study
• Anemia (HCT <38) and Sickle Cell Anemia/Trait, abnormal PT/PTT test or problems with blood clotting
• Present condition of alcoholism, use of nutritional/sports supplements, anabolic steroids, or other substance abuse issues
• Musculoskeletal injuries that compromise the ability to exercise
• Blood donation within 8 weeks of enrollment
• Pregnancy and women not on oral contraceptives

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Load Carriage - Control; Load Carriage - with a calorie-free placebo	Other: Placebo
Experimental: Load Carriage - leucine-enriched nutrition supplement; Load Carriage with leucine-enriched amino acid supplementation	Other: Leucine-enriched nutritional supplement; A protein and carbohydrate supplement with high levels of leucine
Placebo Comparator: Conventional Exercise - Control; Conventional Exercise with a calorie-free placebo	Other: Placebo
Active Comparator: Conventional Exercise - Leucine-enriched Nutrition Supplement; Conventional Exercise with leucine-enriched Amino Acid supplementation	Other: Leucine-enriched nutritional supplement; A protein and carbohydrate supplement with high levels of leucine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in muscle protein synthesis and whole-body protein turnover during and after load carriage or conventional exercise with or without amino acid supplementation	90 min exercise bout (exercise) and 180 min of recovery

Secondary Outcome Measures

Outcome Measure	Time Frame
Changes in muscle performance in recovery from load carriage or conventional exercise with or without amino acid supplementation	4, 24, 48, and 72 hours post exercise

Collaborators and Investigators

• Sponsor: United States Army Research Institute of Environmental Medicine
• Collaborators: US Army Natick Soldier Research, Development & Engineering Center
• Investigators: Principal Investigator: Stefan M Pasiakos, Ph.D., United States Army Research Institute of Environmental Medicine

Publications and helpful links

General Publications

• Margolis LM, McClung HL, Murphy NE, Carrigan CT, Pasiakos SM. Skeletal Muscle myomiR Are Differentially Expressed by Endurance Exercise Mode and Combined Essential Amino Acid and Carbohydrate Supplementation. Front Physiol. 2017 Mar 23;8:182. doi: 10.3389/fphys.2017.00182. eCollection 2017.
• Pasiakos SM, McClung HL, Margolis LM, Murphy NE, Lin GG, Hydren JR, Young AJ. Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition. PLoS One. 2015 Oct 16;10(10):e0140863. doi: 10.1371/journal.pone.0140863. eCollection 2015.
• Margolis LM, Murphy NE, Carrigan CT, McClung HL, Pasiakos SM. Ingesting a Combined Carbohydrate and Essential Amino Acid Supplement Compared to a Non-Nutritive Placebo Blunts Mitochondrial Biogenesis-Related Gene Expression after Aerobic Exercise. Curr Dev Nutr. 2017 May 23;1(6):e000893. doi: 10.3945/cdn.117.000893. eCollection 2017 Jun.

Helpful Links

• Ingesting a Combined Carbohydrate and Essential Amino Acid Supplement Compared to a Non-Nutritive Placebo Blunts Mitochondrial Biogenesis-Related Gene Expression after Aerobic Exercise

Study record dates

Study Major Dates

• Study Start: October 1, 2012
• Primary Completion (Actual): November 1, 2013
• Study Completion (Actual): November 1, 2013

Study Registration Dates

• First Submitted: October 23, 2012
• First Submitted That Met QC Criteria: October 25, 2012
• First Posted (Estimate): October 26, 2012

Study Record Updates

• Last Update Posted (Actual): July 21, 2017
• Last Update Submitted That Met QC Criteria: July 19, 2017
• Last Verified: September 1, 2016

More Information

Terms related to this study

• Other Study ID Numbers: 12-18-HC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No