The Effects of Protein Supplementation With or Without Urolithin A During Single-leg Immobilization

After participants provide informed consent to participate and are deemed eligible for the study (Day 0), participants will sequentially complete the three phases of this study:

• RUN-IN phase: participants continue habitual lifestyle (Day 7-Day 14 [1 week])
• IMMOBILIZATION phase: participants undergo 2 weeks of unilateral knee immobilization (Day 14-Day 28 [2 weeks])
• RECOVERY phase: participants return to habitual lifestyle (Day 28-Day 35 [1 week])

Participants will consume their randomly assigned supplement daily during all three phases.

Inclusion criteria

• Men aged 18-30 years
• Healthy, non-smoking
• BMI between 20 and 30 kg/m^2
• No orthopedic issues that would preclude participation in the knee bracing protocol
• Not taking any medication or with any medical condition that, in the opinion of the investigators, would compromise the study outcome or the safety of the research participant
• Provide informed consent
• Understand COVID-19 risks and procedures for in person research and sign Information Letter: COVID-19 Risks and Procedures for In-Person Research at McMaster University

Exclusion criteria

• Subject has any concurrent medical, orthopedic, or psychiatric requirements that, in the opinion of the investigators, would compromise their ability to comply with the study requirements
• Clinically significant abnormal laboratory results at screening
• Participation in a clinical research trial within 30 days before randomization
• Allergy or sensitivity to study ingredients
• Individuals who are cognitively impaired and/or who are unable to give informed consent
• Any other condition that, in the opinion of the investigators, may adversely affect the subject's ability to complete the study or its measures or may pose a significant risk to the subject
• Any cachexia-related condition or any genetic muscle diseases or disorders
• Current gastrointestinal condition that could interfere with the study (e.g., IBS/IBD [irritable bowel syndrome/inflammatory bowel disease], diarrhea, acid reflux disease, dysphagia, etc.)
• Excessive alcohol consumption (>21 units/week) and/or a smoker (cigarettes or vaping)
• Concomitant use of corticosteroids, antibiotics, any anabolic steroid, creatine, whey protein supplements, casein, branched-chain amino acids (BCAAs) or any other NHP [Natural Health Product], medication or supplement used for muscle strengthening/building within 45 days prior to screening
• Contraindications to an MRI scan (metal implants, metal-based ink tattoo)