Pushing a heavy leg press machine makes the outer part of your thigh muscle grow more than doing leg extensions, because it puts more overall stress on that part of the muscle.
Scientific Claim
Multi-joint leg press exercises are likely to produce greater hypertrophy in the vastus lateralis muscle compared to single-joint leg extension exercises in trained young adults after 8 weeks of training, likely due to greater mechanical load and joint angle-specific tension.
Original Statement
“In contrast, point estimates for the vastus lateralis outcomes favored the multi-joint exercise intervention with posterior probabilities ranging from 0.875 ≤ P ≤ 0.994.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
probability
Can suggest probability/likelihood
Assessment Explanation
The Bayesian posterior probabilities indicate high likelihood but not certainty. The claim correctly avoids overgeneralization and matches the study’s probabilistic language and population.
Evidence from Studies
Supporting (1)
Exercise Selection Differentially Influences Lower Body Regional Muscle Development
The study found that doing leg presses made the big thigh muscle (vastus lateralis) grow more than doing leg extensions, because leg presses use more weight and work the muscle through a bigger range of motion.