The Effect of Muscle Stimulation and Amino Acid Intake on Protein Metabolism During Critical Illness

The goal of this clinical trial is to study how whole-body electrical stimulation combined with amino acid intake affects muscle health in ventilated ICU patients. The main questions to answer are: * Does electrostimulation improve the balance of muscle protein in ICU patients? * Does combining electrostimulation with amino acid help build muscle and prevent muscle loss? Researchers will compare three groups of patients: 1. Sham electrostimulation (no current applied) + the standard nutrition 2. Electrostimulation + the standard nutrition 3. Electrostimulation + a 20g amino acid bolus Participants will: * Receive either real or sham electrostimulation * Get their standard nutrition or a 20g amino acid bolus * Have marked amino acids given through an IV * Have blood samples taken to measure the amino acids and glucose in the blood * Undergo ultrasound of the upper arm to measure the blood flow

Inclusion Criteria: * Aged ≥18 years * Expected to need mechanical ventilation for at least 48 hours, judged by physician * Expected to reach a Richmond Agitation-Sedation Scale (RASS) score of -4 or -5 (complete sedation), judged by physician * Informed consent obtained from the next-of-kin * Able to or are receiving gastric tube feeding * Have an arterial and a venous line in situ Exclusion Criteria: * Spinal cord injury * Previous surgery/local wounds that prohibit whole-body NMES * Conditions that prohibit NMES (such open wounds) * Chronic neuromuscular disorders (such as Amyotrophic lateral sclerosis (ALS)) * Acute Kidney Injury (AKI) II and III * Undergoing continuous veno-venous hemofiltration (CVVH) * Rhabdomyolysis * Neuromuscular blocking agents * In the caloric restriction period of refeeding syndrome * In prone position * Burn wounds * ICD/pacemaker * Pregnant * Deemed not suitable to participate based upon the judgement of the treating intensivist