HME Amino Acid Supplementation for Strength, Performance, and Recovery in Trained Adult Males

This is a parallel-group, double-blind, placebo-controlled pilot RCT conducted in Toronto, Ontario, Canada. Target enrollment is 40 to 50 trained adult males (20 to 25 per arm), each meeting a minimum threshold of at least 3 structured resistance-training sessions per week for at least 1 year. Participants are randomized using variable block sizes (4 and 6) with no stratification, drawn from a single homogeneous high-performance population.

The intervention arm receives HME at its licensed dose (3 g free-form amino acid powder plus one 50 mg slow-release beta-alanine capsule daily); the placebo arm receives a maltodextrin powder and capsule matched for appearance, volume, and taste. Creatine is standardized as an open-label background supplement common to both arms (current users receive study-provided creatine monohydrate 5 g/day; non-users abstain), recorded as a covariate.

The trial comprises a 2-week supplement-only lead-in (habitual training) followed by an 8-week supervised resistance-training phase (3 sessions/week). Assessments occur at Weeks 0, 2, 3, 6, and 10. Week 2 (end of lead-in) serves as the pre-exercise baseline for the primary outcome; the Week 0 to Week 2 change estimates a supplement-only signal. Participants, assessors, and the statistical analyst are blinded; blinding integrity is monitored via the Bang Blinding Index at Weeks 2, 6, and 10. The primary analysis is a linear mixed model testing the Group by Time interaction on composite 1-RM (intention-to-treat), adjusting for baseline strength, dietary protein intake, training load, and dietary pattern.

Inclusion criteria

• Age 18 to 45 years inclusive
• Biological male
• Active competitive athlete in a recognized sport OR certified fitness professional (personal trainer, strength and conditioning coach, or equivalent)
• Minimum 3 structured resistance-training sessions per week for at least 1 year continuously
• Habitual protein intake 1.2 to 2.0 g/kg/day confirmed by 7-day food diary at screening
• Current creatine users willing to use study-provided creatine monohydrate 5 g/day; non-users willing not to initiate creatine during the trial
• Able to provide written informed consent in English
• Willing and able to attend all supervised training sessions and assessment visits for 10 weeks
• Access to a digital kitchen scale or willing to obtain one for food-record completion

Exclusion criteria

• Use of anabolic steroids, SARMs, prohormones, or beta-alanine supplements (other than the study product) within 8 weeks of screening
• Current use of any amino acid supplement or weight-gainer product not cleared by the research coordinator
• Currently in an active competitive season with non-negotiable training demands the investigator determines are incompatible with the supervised programme
• Musculoskeletal injury in the preceding 3 months affecting ability to perform study assessments or training
• Any medical condition, medication, or dietary restriction that in the Medical Officer's opinion would affect the safety or validity of participation
• Participation in another intervention study within 4 weeks of screening
• Unwillingness to standardize creatine intake per protocol (current users) or to abstain from initiating creatine (non-users)