Influence of Leucine Enriched Amino Acids on Myofibrillar and Collagen Protein Synthesis

Influence of Leucine Enriched Amino Acids on Myofibrillar and Collagen Protein Synthesis in Human Skeletal Muscle

The primary objective will be to determine the effect of leucine-enriched essential amino acids (LEAA) compared to carbohydrate placebo on dietary incorporation of [D5] Phenylalanine & [D5] Glycine into the three skeletal muscle protein pools (myofibrillar, sarcoplasmic and collagen), both following resistance exercise and at rest, with the two tracers provided as a 'intrinsically labeled' bolus. Other outcomes will relate to molecular regulation of protein synthesis.

Inclusion Criteria:

• Healthy, male and female, recreationally-active participants.
• Healthy will be defined as screened by the PAR-Q+ (The Physical Activity Readiness Questionnaire for everyone; Appendix B).
• Self-reported not having engaged in resistance exercise and/or lower body plyometrics for at least 3 months prior to the study.
• Participants will be aged 18-35 years old.
• Participants are willing to abide by the compliance rules of this study.
• Self-reported regular menstrual cycle (25-35d) within the last 3 months (female participants).

Exclusion Criteria:

• Inability to adhere to any of the compliance rules judged by principle investigator or medical doctor.
• Self-reported regular tobacco use.
• Self-reported illicit drug use (e.g. growth hormone, testosterone, etc.).
• Individuals who have participated in studies within the past year involving any of the stable isotopes in the study.
• Use of birth control and discontinued use within the last 3 months (female participants).