Does cardio slow muscle growth?
Short answer
On average, no. In a meta-analysis of 43 studies, muscle size and maximal strength improved just as much with added endurance training as without. Only explosive strength suffered somewhat, mostly when both were done in the same session.
Figures
- 43 · studies, at least 4 weeks
- ≥ 3 h · gap protected explosive strength better
- -0.01 (95% CI: -0.16–0.18) effect size: Muscle growth
- -0.06 (95% CI: -0.2–0.09) effect size: Maximal strength
- -0.28 (95% CI: -0.48–-0.08) effect size: Explosive strength
What the analysis shows
Schumann and colleagues compared strength training alone with strength plus endurance training. They found no difference for muscle growth or maximal strength. Explosive strength improved somewhat less with the combination, more so when both were in one session than with at least 3 hours between them.
How to use it
If jumping or sprinting matters to you, put endurance work on other days or a few hours apart. Otherwise, plan whatever fits your week.
Limits
Participants were untrained or recreationally active. The analysis says little about athletes with very high endurance volumes.
Sources
- Compatibility of Concurrent Aerobic and Strength Training for Skeletal Muscle Size and Function: An Updated Systematic Review and Meta-Analysis · Schumann M; Feuerbacher JF; Sünkeler M; Freitag N; Rønnestad BR; Doma K; Lundberg TR · 2022 · Sports Med PubMed DOI Study note
Meta-analysis, 43 studies on concurrent training.
Summaries by SetCtl, not medical advice.