The Study
Neurochemical mechanism of muscular pain: Insight from the study on delayed onset muscle soreness
This study is like a teacher explaining what scientists think happens inside muscles when they get sore after exercise, based on experiments in rats. It doesn’t prove exactly how it works in people, but it gives us a good guess based on lab research.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
When muscles feel sore after exercise, it's not because they're damaged—it's because the nerves in the muscle get extra sensitive. In rats, this soreness comes from chemicals in the muscle turning up the 'pain volume' in nerves.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 51 / 100
Quality score
Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means feeling sore after a workout doesn't mean you're building muscle or causing damage—it just means your nerves are reacting to chemical signals.
- 2Soreness starts 1 day after exercise, peaks at 2–3 days, and goes away by day 4.
- 3Rats felt muscle pain even when their muscles weren't damaged.
- 4Blocking certain pain chemicals (like bradykinin and NGF) stopped or reversed the soreness.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Physiological Sciences : JPS
Year
2024
Authors
K. Mizumura, T. Taguchi
Related Content
Claims (6)
Feeling sore after a workout doesn’t mean you’re building muscle or that your workout was effective — DOMS isn’t a good way to measure progress.
Even if a rat's muscles aren't actually torn or damaged, it can still feel sore after exercise — this soreness seems to come from nerve sensitivity, not from physical damage, especially when the exercise isn't too intense.
In rats, sore muscles after unusual exercise seem to start with a specific pain signal (called bradykinin) turning on right when the exercise happens. If you block that signal before exercise, the rats don’t get sore — but only if you block it early.
In rats with muscle soreness after exercise, two brain-chemical pathways team up to make muscles extra sensitive to pain, especially when certain pain-related proteins are present at low levels — and they both work through specific pain sensors in the nerves.
When rats do certain muscle exercises, they get sore deep in their muscles—not on the skin—starting a day later, peaking after 2–3 days, and going away by day 4. This soreness is due to increased sensitivity in the muscles themselves.
In rats, sore muscles after unusual exercise make a protein called NGF, which seems to cause pain sensitivity—blocking NGF quickly reduces soreness, and stopping another pain-related signal (bradykinin) also stops NGF from being made, suggesting it's part of the soreness chain reaction.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.