01/25/2026
Traditional View vs. Current Understanding
For years, the idea was popular that lifting weights causes tiny "micro-tears" in muscle fibers, inflammation follows, the body repairs them stronger/bigger (via elevated muscle protein synthesis), and that's how growth happens. This stems from older models (e.g., around 2010) that listed three main mechanisms for hypertrophy:
Mechanical tension (force/stretch on muscle fibers)
Metabolic stress (buildup of metabolites like lactate during higher-rep sets)
Muscle damage (micro-tears and inflammation)
While all three can contribute, newer research (especially from the last ~5–10 years, with summaries in 2023–2025 sources) shows that muscle damage is not essential and often doesn't correlate strongly with growth.
Studies and reviews indicate that hypertrophy can occur with minimal to no significant muscle damage — for example, in well-trained people using controlled, moderate protocols that emphasize tension without extreme novelty or eccentric overload.
High damage (e.g., from lots of eccentric-focused training, new exercises, or very high volumes when unaccustomed) can actually impair recovery and reduce the ability to train consistently with high tension/volume over time.
Mechanical tension (especially under load with sufficient range of motion and effort close to failure) reliably triggers the signaling pathways (like mTOR) for muscle protein synthesis and growth, even when damage markers are low.
Supporting Evidence from Recent Sources
Multiple 2024–2025 articles and expert summaries explicitly call the "micro-tears are required" idea a myth or outdated. For instance, mechanical tension is described as the primary or main driver, while damage is secondary or dispensable.
You can achieve solid hypertrophy with progressive overload focused on tension and volume (e.g., 6–10 rep ranges, multiple sets per muscle group per week) without chasing soreness or extreme damage.
Protein synthesis ramps up from tension and nutrition (especially leucine-rich protein intake post-workout), not solely from repairing tears.
Practical Takeaway
To grow muscle effectively:
Prioritize progressive mechanical tension: Lift challenging weights with good form, full range of motion, and get close to (or to) failure in most sets.
Accumulate sufficient volume: Typically 10–20+ hard sets per muscle group per week, spread across sessions.
Recover well: Nutrition (protein ~1.6–2.2g/kg bodyweight), sleep, and manage fatigue so you can keep applying tension consistently.
Don't chase soreness or DOMS — it's not a reliable indicator of growth and can signal unnecessary damage.