HAVE YOU HEARD?
Every Sunday, Coach Lionel decodes the latest research in strength, nutrition, and performance science. No fluff. No hype. Just what the data says — and what it means for your training.
A comprehensive review from McMaster University — one of the world's top exercise science labs — systematically dismantled three of the most persistent myths in resistance training. Led by researchers Van Every, Lees, Wilson, Nippard, and Phillips, the team synthesized decades of controlled studies to find out what actually causes muscle hypertrophy.
The verdict: mechanical tension is the only proven primary driver of muscle growth. The post-workout testosterone spike, the "anabolic window" created by metabolic stress, the pump from blood pooling in the muscle — none of these have causal evidence for driving hypertrophy. They're side effects of training, not the mechanism.
Critically, they found that acute elevations in testosterone, growth hormone, and IGF-1 after exercise do not enhance muscle protein synthesis or hypertrophic outcomes — in either men or women. One landmark unilateral training study saw a 22% increase in muscle cross-sectional area in the trained leg with zero change in systemic hormone levels.
- Stop chasing the pump as proof your workout worked. Chase progressive overload instead.
- High-rep "feel the burn" sets and heavy low-rep sets produce equal hypertrophy when volume is matched — pick what you can recover from and progress on.
- The post-workout anabolic window is not driven by your hormone spike. Total daily protein and weekly volume matter far more.
- Realistic gains: ~1–2 kg of lean mass per 8–12 week training block. Plateau is normal as experience increases.
- Mechanical tension = progressive resistance + proximity to failure. That's the entire formula.
A multidimensional review published in the Journal of Clinical Medicine analyzed the full physiological and molecular cascade that occurs when athletes consistently under-sleep. The findings are a direct counterargument to "grind culture" in fitness.
During deep sleep (Stage N3), the body executes the majority of its anabolic work: growth hormone surges, testosterone and IGF-1 are secreted, and muscle protein synthesis peaks. Cut that window short and all three crash simultaneously. A single night of poor sleep reduces testosterone by nearly one-quarter. Chronic restriction — even just 5–6 hours per night over several days — reduces muscle protein synthesis by up to 18–20% and pushes the body into catabolic dominance via elevated cortisol.
The review also confirmed that sleep deprivation impairs glycogen resynthesis — meaning you can't fully refuel between sessions — and significantly increases injury risk by degrading movement accuracy, tissue resilience, and reaction time.