Muscles don’t grow evenly—when you train your thigh, the top and middle parts of the front muscle grow more than the bottom, and the side muscle grows the same everywhere.
Scientific Claim
Hypertrophy of the quadriceps femoris in response to resistance training is non-uniform along the muscle length, with the rectus femoris showing greater growth in proximal and mid regions than distal regions, and the vastus lateralis showing minimal regional variation, as demonstrated by ultrasound measurements at 30%, 50%, and 70% of muscle length in recreationally active young men.
Original Statement
“Our findings indicate that changes in muscle size varied considerably along the length of the muscles studied, as demonstrated in previous research. Thus, to obtain a true understanding of muscular adaptations pursuant to longitudinal RT designs, researchers should endeavor to measure hypertrophy at proximal, middle, and distal sites when investigating hypertrophic changes of the quadriceps.”
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 study directly measured regional hypertrophy at three sites with high reliability (ICC >0.92), and the observed variation is a factual outcome of the data, not an overinterpretation.
Evidence from Studies
Supporting (1)
Drop-Set Training Elicits Differential Increases in Non-Uniform Hypertrophy of the Quadriceps in Leg Extension Exercise
The study found that the front thigh muscle grows more in the upper and middle parts than the bottom, while the side thigh muscle grows evenly all along — just like the claim says.