After a tough bicep workout, your arm gets a little swollen, but it goes back to normal by the next day — and it doesn’t matter if you changed your shoulder angle during the workout.
Scientific Claim
Acute muscle swelling in the biceps brachii increases by approximately 12% immediately after resistance training and returns to baseline within 24 hours in resistance-trained individuals, regardless of whether glenohumeral joint angles are varied or held constant.
Original Statement
“For mid-belly muscle swelling, there was a main time effect (p = 0.0001) indicating that muscle swelling was greater at post compared to baseline (95%-CI: 0.35 to 0.56 cm)... The muscle swelling returned to baseline 24 h post similarly across conditions.”
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 RCT design with repeated ultrasound measurements and statistical analysis supports a definitive causal claim about acute swelling dynamics.
Evidence from Studies
Supporting (0)
Contradicting (1)
The study looked at whether changing arm position during bicep curls affects muscle swelling, but it didn’t say how much the muscles swelled or when they went back to normal — so we can’t tell if the claim about a 12% increase and 24-hour recovery is true.