The Study
Muscle damaging eccentric exercise attenuates disuse-induced declines in daily myofibrillar protein synthesis and transiently prevents muscle atrophy in healthy men
This study watched what happened to muscle in a small group of young men when one leg was kept still, with or without a hard workout first. It can show that the workout was linked to less muscle loss at first, but it can't prove the workout caused it because we don't know for sure how people were picked for each group.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if doing super-hard leg exercises before not moving for a week helps keep muscles from shrinking.
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 559 / 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.
- 1The early protection might help right after an injury when movement is limited, but it doesn’t prevent long-term muscle loss.
- 2After 2 days, the group that did hard exercises didn’t lose muscle, but the others did (0% vs 1.7% loss).
- 3By day 7, both groups lost about the same (4–5%).
- 4The exercise group had 48% higher muscle repair activity at first.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
American Journal of Physiology - Endocrinology and Metabolism
Year
2021
Authors
T. Jameson, Sean P. Kilroe, J. Fulford, D. Abdelrahman, A. Murton, M. Dirks, F. Stephens, B. Wall
Related Content
Claims (6)
If young, healthy guys do certain tough leg exercises before keeping one leg still, they might avoid losing muscle in that leg during the first couple of days of not using it.
If young, healthy guys do certain muscle-damaging exercises before their leg is immobilized, their muscles might waste away less—even if their muscle-building activity goes down. Without those exercises, lower muscle-building activity means more muscle loss.
If young, healthy guys do a tough leg workout right before having one leg immobilized for a week, their muscles in that leg keep building protein faster for the first couple of days compared to if they didn’t exercise first.
If young, healthy guys do certain muscle-lengthening exercises before having one leg kept still for a week, their muscles don’t slow down making new proteins as much as those who don’t exercise — which might help prevent muscle loss.
If young, healthy guys do certain muscle exercises before having one leg kept still for a week, it doesn’t really help keep the muscle from shrinking — both those who did the exercises and those who didn’t lost about the same amount of muscle.
If you suddenly do really intense stretching-type workouts that your muscles aren't used to, it can seriously damage them — so much that the muscles actually get smaller for a few weeks.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.