Effects of Protein Quality on Post-exercise Skeletal Muscle and Whole-body Protein Kinetics During Energy Deficit

Effects of Protein Quality on Post-exercise Skeletal Muscle and Whole-body Protein Kinetics During Negative Energy Balance

The optimal EAA-containing protein format necessary to maximally stimulate muscle protein synthesis and optimize whole-body net protein balance during caloric deprivation has not been determined. This study will address that gap in knowledge by examining post, whole-body exercise muscle and whole-body protein kinetic responses to ingesting varying EAA-containing protein formats after a 5 day period of negative energy balance. This study will provide the initial evidence to support the development of a recovery-based food product for military combat rations.

Ten resistance-trained adults will complete this ~55-d randomized, cross-over study. Participants will participate in three, non-consecutive 5-d controlled energy deficit periods, each separated by a 14-d washout period (i.e., sufficient time to restore nitrogen and metabolic homeostasis after moderate weight loss). Post-exercise (whole-body exercise model) muscle protein synthesis (MPS) and whole-body protein turnover responses to varying EAA-containing protein formats will be determined the morning after completing the 5-d energy deficit.

Inclusion Criteria:

• Men and women aged 18 - 35 years
• Body mass index < 30.0 kg/m2
• Healthy without evidence of chronic illness or musculoskeletal injury as determined by the USARIEM Office of Medical Support and Oversight (OMSO) or home duty station medical support
• Resistance exercise trained defined by self-report as performing ≥ 2 sessions/wk for previous 6 mo
• Refrain from taking any nonsteroidal anti-inflammatory drugs (e.g., aspirin, Advil®, Aleve®, Naprosyn®), or any other aspirin-containing product for 10 days before starting and at least 5 days after completing the study
• Willing to refrain from alcohol, smoking any nicotine product (includes e-cigarettes); vaping, chewing tobacco, caffeine, and dietary supplement use throughout the entire study period
• Supervisor approval for federal civilian employees and non-HRV active duty military personnel working within the US Army Natick Soldier Systems Center

Exclusion Criteria:

• Musculoskeletal injuries that compromise exercise capability as determined by the USARIEM or home duty station Office of Medical Support and Oversight (OMSO)
• Metabolic or cardiovascular abnormalities, gastrointestinal disorders (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
• Abnormal PT/PTT test or problems with blood clotting
• History of complications with lidocaine
• Present condition of alcoholism, anabolic steroids, or other substance abuse issues
• Blood donation within 8-wk of beginning the study
• Pregnant, trying to become pregnant, and/or breastfeeding (results of urine pregnancy test or self-report for breastfeeding will be obtained before body composition testing)
• Unwillingness or inability to consume study diets or foods provided