Effects of Essential Amino Acid-enriched Whey and Carbohydrate Co-ingestion on Protein Kinetics

In this study the Investigators will test the effects of EAA-enriched whey protein plus carbohydrate versus EAA-enriched whey plus additional EAA using a randomized, cross-sectional longitudinal study design. Thirty healthy, functional and aerobic exercise trained adults will complete two, 5-d controlled feeding phases, one maintaining energy balance and one inducing energy deficit in random order and separated by at least a 7d washout period. The difference in post-exercise (whole-body exercise model) muscle protein synthesis and whole-body protein turnover between the study treatments will be determined the day after each 5-d controlled feeding phase. This design will test the following hypotheses: 1) The magnitude of post-exercise anabolic response to EAA-enriched whey protein plus carbohydrate are enhanced compared to EAA-enriched whey protein plus additional EAA during energy deficit; 2) Regardless of protein treatment, the magnitude of anabolic response will be reduced during energy deficit compared to energy balance.

Inclusion criteria

• Body mass index < 30.0 kg/m2
• Weight stable in the past 2 months (± 2.27 kg)
• 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
• Functional exercise (i.e., step ups, box jumps, body mass movements) and/or aerobic exercise trained defined by self-report as performing ≥ 2 sessions/wk for previous 6 months
• Willing to refrain from taking any nonsteroidal anti-inflammatory drugs (e.g., aspirin, Advil®, Aleve®, Naprosyn®), or any other aspirin-containing product for 10 days before the first ~8.5 hour laboratory day and at least 5 days after completing the last ~8.5 hour laboratory day
• Willing to refrain from alcohol, smoking any nicotine product (includes e-cigarettes), vaping, chewing tobacco, caffeine, and dietary supplements after the completing the baseline period until the end of the study
• Must obtain supervisor approval for federal civilian employees and non-HRV active duty military personnel working within the US Army Natick Soldier Systems Center
• Females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or able to provide documentation of oral/hormonal contraceptive use which contains low-dose estrogen/progesterone to maintain continuous levels throughout the 28-day cycle (i.e., no placebos)

Exclusion criteria

• 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 as assessed by OMSO
• Participation in 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 due to personal preference, dietary restrictions, and/or food allergies
• Unwillingness to adhere to study physical restrictions