The Finding
Regaining lost muscle takes approximately 30% of the time it originally took to build it.
A 2025 study in the Scandinavian Journal of Medicine and Science in Sports found that previously trained individuals who took a 10-week break regained all lost progress in 5 weeks of retraining.
How It Works
There are three mechanisms behind this.
Professor Kevin Murach (University of Arkansas): "You have more of these control centers and they can basically cause more rapid adaptation the second time around."
How Fast Do You Lose It
- Strength holds for ~3-4 weeks without training
- Loss is gradual after that
- Endurance drops faster: 4-25% in 3-4 weeks
Returning to Training
- Compound movements first: squats, deadlifts, rows, presses
- Don't rush. Injury is the only real setback.
- Protein: 1.6-2.2g/kg daily during the rebuild
- Creatine: 5g/day supports strength recovery (and has cognitive benefits)
Reference
- Raby, K. et al. (2025). Scientists Reveal Why Regaining Lost Muscle Takes Just 30% of the Original Time. Scandinavian Journal of Medicine and Science in Sports