🧬 What Is Hypertrophy?
Muscle hypertrophy is an increase in muscle fiber thickness. Unlike hyperplasia (creation of new cells), hypertrophy increases the size of existing cells. This is the main way muscles grow with training.
🔬 3 Main Mechanisms of Hypertrophy
- Mechanical tension — heavy weights, tensile forces in the muscles. This is the main signal to grow.
- Metabolic stress — the "pump" sensation, lactate accumulation, blood rush. Creates an anabolic environment.
- Muscle damage — microtears in muscle fibers. The body repairs them thicker and stronger.
📊 Optimal Parameters for Hypertrophy
6-12
Repetitions per set
3-5
Sets per exercise
60-90 sec.
Rest between sets
10-20
Sets per muscle group/week
2-3×/week
Frequency per muscle group
65-85%
% of 1RM
🏋️ Progressive Overload
This is the most important principle. Muscles grow only when they are given a greater load than they are accustomed to. Each week, try to:
- Increase the weight by 1-2.5 kg
- Or increase the number of repetitions by 1-2
- Or add one additional set
- Or shorten rest between sets