The Study
Skeletal muscle adaptations to high‐intensity, low‐volume concurrent resistance and interval training in recreationally active men and women
This study watched what happened to people after they did a specific workout for 12 weeks. It saw that their muscles got stronger and some parts changed, but it didn't compare them to people who didn't do the workout. So we can't say the workout definitely caused the changes—maybe they were already changing for other reasons.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
People did short, tough workouts three times a week for 12 weeks — lifting heavy and doing sprint-like moves — to see if they got stronger and their muscles changed.
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 547 / 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 — you can get stronger and build muscle with minimal training time, but if you want better cardio, you need more aerobic-specific work.
- 2Men’s muscle fibers grew by about 13%; women’s didn’t.
- 3Both sexes got stronger, gained lean mass, and their muscles shifted toward more fatigue-resistant types.
- 4But their heart/lung fitness didn’t improve.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Physiological Reports
Year
2024
Authors
Adam J. Sterczala, Nathaniel Rodriguez-Ortiz, Evan D. Feigel, K. Krajewski, Brian J Martin, Nicole M Sekel, M. Lovalekar, Chris K Kargl, Kristen J. Koltun, C. V. van Eck, Shawn D. Flanagan, Chris Connaboy, S. Wardle, T. O’Leary, J. Greeves, B. Nindl
Related Content
Claims (6)
People who have previously built muscle can maintain that muscle with low training volume if they train at high intensity.
After 12 weeks of high-intensity, low-volume concurrent training, recreationally active men experience a 12.9% increase in type I muscle fiber size and a 12.7% increase in type IIa muscle fiber size, while recreationally active women do not show similar increases in these muscle fiber sizes, even though both groups gain equal strength and lean body mass.
After 12 weeks of high-intensity, low-volume combined strength and endurance training, the proportion of type IIx muscle fibers decreases by about 1.9% in men and women, while the number of capillaries and COX IV protein levels remain unchanged.
After 12 weeks of high-intensity, low-volume combined endurance and strength training, skeletal muscle shows a 29.7% increase in PGC-1α and an 11.0% increase in citrate synthase, but no change in COX IV levels.
After 12 weeks of a specific high-intensity training program that combines strength and interval exercises, recreationally active men and women gain muscle strength and lean body mass, but their aerobic endurance does not improve.
In recreationally active men and women, a 12-week concurrent training program that improves strength and muscle mass does not increase aerobic capacity (VO2peak).
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.