Even though testosterone levels go up during a heavy workout, the muscle’s testosterone receptors don’t change in number two days later in trained men.
Scientific Claim
Androgen receptor mRNA and protein expression in the vastus lateralis muscle show no statistically significant change 48 hours after heavy resistance exercise in strength-trained men, despite acute increases in serum testosterone.
Original Statement
“No statistically significant changes were observed in mean AR protein concentration or mRNA expression after the exercise in comparison to the pre-exercise values.”
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 reports the absence of change as a measured association, avoiding causal language. The design supports detection of within-subject null effects.
Evidence from Studies
Supporting (1)
Even though the men’s testosterone levels shot up after their workout, their muscle cells didn’t show more androgen receptors 48 hours later — so the claim that testosterone spikes don’t immediately change these receptors is backed up by the data.