According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Randomized Controlled Trial with isolated mechanical tension manipulation
A randomized controlled trial in healthy adult humans comparing resistance training with mechanical tension isolated via load-controlled devices (e.g., isometric contractions with blood flow restriction to eliminate metabolic stress) versus resistance training with added hormonal/metabolic stressors (e.g., high-rep sets with short rest). Muscle hypertrophy and protein synthesis rates are measured via MRI and stable isotope labeling over 12 weeks. Comparator groups include non-loaded control and hormonal suppression (e.g., GnRH analogs) to isolate mechanical tension effects. Mechanistic human biopsy study with pathway inhibition
A within-subject human study where participants perform unilateral resistance training while pharmacologically inhibiting mTORC1 (e.g., rapamycin infusion) or FAK (e.g., small molecule inhibitor) in one limb, while the contralateral limb receives placebo. Muscle biopsies are taken pre- and post-intervention to measure hypertrophy and anabolic signaling markers. The design isolates the necessity of these pathways for tension-induced hypertrophy. Controlled mechanical stimulation in vivo human model
A study using a non-exercise mechanical tension device (e.g., wearable tension apparatus applying controlled strain to quadriceps without voluntary contraction) applied daily to one limb, compared to sham device on the other limb. Hormonal and metabolic markers are monitored to confirm absence of stress responses. Hypertrophy and protein synthesis are measured over 10 weeks. Longitudinal observational study with biomechanical quantification
A 6-month longitudinal study tracking resistance-trained individuals with detailed biomechanical analysis (force plates, EMG, motion capture) to correlate peak mechanical tension during lifts with muscle growth, while controlling for hormonal profiles (salivary cortisol, testosterone) and metabolic markers (lactate, AMPK). In vitro human myotube study with mechanical stretch
Human primary myotubes subjected to cyclic mechanical stretch in a bioreactor (mimicking resistance training strain) with and without mTORC1/FAK inhibitors, in the absence of growth factors or metabolic stressors. Protein synthesis and pathway activation are measured.