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Back to Study: Cluster sets and traditional sets elicit similar m...
correlational
Analysis v1
45
Pro
0
Against

When muscles get bigger from lifting weights, the way we measure it (ultrasound vs. body scan) doesn’t always line up—so they might be capturing different kinds of changes, not just muscle growth.

Scientific Claim

Muscle thickness increases measured via ultrasound at the mid-thigh rectus femoris are not strongly correlated with changes in thigh lean tissue mass measured by DXA in resistance-trained individuals undergoing either cluster or traditional training, suggesting these measures may reflect different aspects of tissue adaptation.

Original Statement

“In addition, no statistically significant (p > 0.05) correlations were found between changes in muscle thickness and lean mass for both the CS (R = 0.009) and TS (R = 0.506) groups.”

From study:Cluster sets and traditional sets elicit similar muscular hypertrophy: a volume and effort-matched study in resistance-trained individuals

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The claim correctly describes a correlation observed in the data without implying causation. The language is appropriate for a correlational finding from a within-subject design.

Evidence from Studies

Supporting (1)

45
45

Cluster sets and traditional sets elicit similar muscular hypertrophy: a volume and effort-matched study in resistance-trained individuals

Randomized Controlled Trial
Human
2025 Jun

The study found that both types of workouts made thighs bigger and leaner, but didn’t show that how much the muscle looked bigger on ultrasound matched up tightly with how much lean mass increased on the DXA scan—so they’re probably measuring different things.

Contradicting (0)

0
No contradicting evidence found

Source Study

Cluster sets and traditional sets elicit similar muscular hypertrophy: a volume and effort-matched study in resistance-trained individuals

Score: 45
DOI: 10.1007/s00421-025-05712-6

Similar Assertions

Even though both muscle thickness and total lean mass went up after training, they didn’t change together in a predictable way—meaning one might not be a perfect stand-in for the other.

45
0
79%

Measuring thigh muscle thickness with ultrasound near the top and middle of the thigh is a good way to see if your muscles are growing from training—but measuring near the knee might not show it.

54
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75%

This study only looked at the front and side of the thigh—so we don’t know if doing more sets helps your front thigh or hamstrings grow more.

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52
72%

If you’re already experienced with weightlifting and train your legs twice a week for 8 weeks with hard sets, your muscles will grow whether you take short breaks between reps or not.

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72%

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.

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0
72%