If you're already strong and experienced, you can choose to do either full reps or half-reps at the stretch — both will make your arms bigger and stronger about the same amount.
Scientific Claim
The muscle hypertrophy and strength-endurance adaptations observed in resistance-trained individuals after 8 weeks of upper-body training are not significantly influenced by whether the training is performed with full range of motion or lengthened partials, indicating that both methods are equally effective for these outcomes.
Original Statement
“Both muscle thickness and unilateral lat pulldown 10-repetition-maximum improvements were similar between the two conditions. Results were consistent across outcomes with point estimates close to zero, and Bayes factors (0.16 to 0.39) generally providing 'moderate' support for the null hypothesis of equal improvement across interventions.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The RCT design with Bayesian analysis provides strong causal evidence for equivalence. The claim uses 'not significantly influenced' and 'equally effective' — precise, accurate language for this level of evidence.
Gold Standard Evidence Needed
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.
Systematic Review & Meta-AnalysisLevel 1aWhether the equivalence between LPs and full ROM for hypertrophy and strength-endurance holds across multiple studies in trained populations.
Whether the equivalence between LPs and full ROM for hypertrophy and strength-endurance holds across multiple studies in trained populations.
What This Would Prove
Whether the equivalence between LPs and full ROM for hypertrophy and strength-endurance holds across multiple studies in trained populations.
Ideal Study Design
A meta-analysis of 12+ RCTs comparing LPs vs. full ROM in resistance-trained adults, measuring muscle thickness via ultrasound and strength-endurance via 10RM across upper-body exercises, with standardized volume, intensity, and stretch emphasis.
Limitation: Cannot determine optimal training variables or long-term effects beyond 8–12 weeks.
Randomized Controlled TrialLevel 1bWhether the equivalence extends to other muscle groups (e.g., quadriceps, glutes) and longer durations (16–24 weeks).
Whether the equivalence extends to other muscle groups (e.g., quadriceps, glutes) and longer durations (16–24 weeks).
What This Would Prove
Whether the equivalence extends to other muscle groups (e.g., quadriceps, glutes) and longer durations (16–24 weeks).
Ideal Study Design
A double-blind, within-participant RCT with 60 trained individuals, assigning limbs to LPs or full ROM for 24 weeks across 8 upper- and lower-body exercises, measuring muscle thickness via ultrasound and strength-endurance via 10RM, with strict volume control.
Limitation: Cannot generalize to untrained populations or non-resistance-trained athletes.
Longitudinal Cohort StudyLevel 2bWhether long-term adherence to LPs vs. full ROM leads to different outcomes in real-world training environments.
Whether long-term adherence to LPs vs. full ROM leads to different outcomes in real-world training environments.
What This Would Prove
Whether long-term adherence to LPs vs. full ROM leads to different outcomes in real-world training environments.
Ideal Study Design
A 3-year prospective cohort of 300 resistance-trained individuals self-selecting LPs or full ROM, with quarterly ultrasound and strength testing, controlling for volume, nutrition, and recovery.
Limitation: High risk of self-selection bias and inconsistent adherence.
Evidence from Studies
Supporting (1)
The study found that lifting weights with a full motion and lifting with only the stretched part of the movement both built muscle and improved endurance equally well in trained people, so neither method is better than the other.