Analysis Version
v1
History
Back to Study: Reduced muscle lengthening during eccentric contra...
descriptive
Analysis v1
37
Pro
0
Against

We know muscles stretch less the second time you do a tough workout, but we don’t yet know why that happens.

Scientific Claim

The repeated-bout effect in untrained men is associated with reduced muscle lengthening during eccentric contractions, but the underlying mechanisms causing this reduction (e.g., tendon compliance, neural adaptation, connective tissue remodeling) remain unidentified.

Original Statement

“It is not known how this happened; however, it could be speculated that the muscle became stiffer, or the tendon became more compliant after performing ECC1... Thus, further study is warranted to examine this speculation.”

From study:Reduced muscle lengthening during eccentric contractions as a mechanism underpinning the repeated-bout effect.

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 uses 'associated with' and explicitly states mechanisms are unidentified, matching the authors’ cautious interpretation.

Evidence from Studies

Supporting (1)

37
37

Reduced muscle lengthening during eccentric contractions as a mechanism underpinning the repeated-bout effect.

Randomized Controlled Trial
Human
2015 May 15

The study found that after doing the same arm exercise twice, the muscles stretched less the second time—which helped them get less sore and damaged—but it didn’t figure out why the muscles stretched less.

Contradicting (0)

0
No contradicting evidence found

Source Study

Reduced muscle lengthening during eccentric contractions as a mechanism underpinning the repeated-bout effect.

Score: 37
DOI: 10.1152/ajpregu.00338.2014

Similar Assertions

Your muscles learn to handle hard eccentric moves quickly—after just 10 weekly sessions, they stop getting damaged even if you do them at max effort.

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Your muscles adapt to hard eccentric exercise faster than you think—after just 10 weekly sessions, they stop showing any signs of damage.

58
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Even if you only train one way—like pushing weights up—your body still learns to handle hard eccentric movements without damage, suggesting the adaptation is whole-body, not just local.

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When people who don't normally lift weights do a tough arm exercise twice, four weeks apart, their biceps don't stretch as much the second time, even though they're trying just as hard.

37
0
72%