The Study
Damage and the repeated bout effect of arm, leg, and trunk muscles induced by eccentric resistance exercises
This study looked at how muscles react to a specific type of workout in just 15 people. It can show us what happened to these specific individuals, but it cannot prove that the workout definitely causes these results for everyone else. We can only say what was observed, not that it's a proven rule.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Researchers tested how untrained men's muscles react to a single intense workout and what happens when they do it again two weeks later.
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 540 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, this shows that doing a new intense exercise once actually protects your muscles from future damage, which is why gradual progression is key in training.
- 2One workout caused strength drops of 16-57%, soreness up to 70mm, and massive muscle protein spikes in the blood.
- 3Doing it again after two weeks greatly reduced all these negative effects, and blood protein levels stayed normal.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Scandinavian Journal of Medicine & Science in Sports
Year
2019
Authors
T. Chen, Tsung-Jen Yang, Min-Jyue Huang, Ho-Seng Wang, Kuo‐Wei Tseng, Hsin-Lian Chen, K. Nosaka
Related Content
Claims (4)
If you do a tough, unfamiliar full-body workout and then repeat the exact same workout two weeks later, your body will experience much less muscle soreness, strength loss, and tissue damage. This shows that your muscles quickly adapt to the same type of stress, protecting you from injury the second time around.
When people who don't exercise regularly try a new type of strength workout that focuses on lengthening muscles, their upper body and back muscles get much weaker and more sore than their leg muscles. This shows that different parts of the body are more sensitive to the stress of unfamiliar exercise.
Doing a new, intense workout that focuses on lengthening muscles under tension can cause temporary muscle damage and soreness. This shows up as a noticeable drop in strength, higher pain levels, and a spike in a specific muscle enzyme in the blood for up to four days.
Doing a tough workout twice in a row actually protects your muscles from damage. After your first really hard session, your body adapts so that your next session won't cause muscle proteins to leak into your bloodstream like it did the first time.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.