People who train both legs together show bigger increases in muscle electrical activity during double-leg lifts than those who train one leg at a time, suggesting their nervous systems become more active during those movements.
Scientific Claim
Twelve weeks of progressive heavy resistance training is associated with a 19% increase in integrated electromyographic (IEMG) activity during bilateral knee extensions in bilateral-trained individuals, which is greater than the 10% increase observed in unilateral-trained individuals.
Original Statement
“The relative average increase of 19±19% (P<0.001) observed in the maximum averaged IEMG of both legs during the bilateral actions in all BIL trained subjects was greater (P<0.05) than that of 10±17% (P<0.05) recorded for all UNIL trained subjects.”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
Causal language like 'leads to' or 'produces' is used in the abstract, but without confirmed randomization, only associations can be claimed.
Evidence from Studies
Supporting (1)
Neuromuscular adaptations during bilateral versus unilateral strength training in middle-aged and elderly men and women.
People who trained both legs at the same time got a bigger boost in muscle nerve activity during double-leg exercises than those who trained one leg at a time — exactly as the claim says.