Plant-based proteins contain several amino acids that are essential to signal growth, reconditioning, maintenance and preservation of skeletal muscle mass. This study aims to inform on the nutrient activation of muscle protein synthesis (MPS) by feeding a plant protein isolate equivalent to 0.33 g of protein per kilogram of body mass.

Participants: 32 young, healthy men and women aged 18 - 35 years. Intervention: Plant protein isolate (PPI) and nonessential amino acid control (NEAA) Study Design: Block randomised control trial. Two group parallel design. Primary outcome: Myofibrillar fractional synthetic rate (myoFSR).

Preliminary screening/familiarization consists of: medical history, dietary assessment and examination by a medical doctor and a qualified dietician, blood sample to be evaluated for health-related contraindications, body composition measurement by dual energy x-ray absorptiometry (DXA), isokinetic knee extensor strength tests.

Pre-trial: A metered dose of deuterium oxide (5ml/kg) will be ingested and blood and/or saliva (~5ml) samples will be collected pre/post ingestion.

Experimental trial: Blood, saliva and bilateral m.vastus lateralis microbiopsies (~100 mg) collected. A unilateral resistance-training session consisting of knee extensor contractions will be completed. Following exercise cessation participants will ingest 0.33 g/kg body mass of either: a nonessential amino acid formulation or a plant-protein isolate. A saliva sample and a 2nd set of bilateral m.vastus lateralis microbiopsies are collected 3 h postingestion.

Inclusion Criteria:

- Men and women aged 18 to 35 years

Exclusion Criteria:

• Known intolerance to any item contained in the protein products.
• Blood borne disease risk, current illness or medication that would adversely affect participation
• Known adverse reaction to venepuncture and/or biopsy
• Inability to undertake resistance exercise
• Inability to adhere to protocol guidelines

Single blind (participant)