Muscle Fiber Types: Training for Type I vs Type II Fibers
TL;DR: Type I (slow-twitch) = endurance. Type II (fast-twitch) = strength/power. Train with varied rep ranges to hit both fiber types.
Programming by fiber bias
- Type II dominant muscles (quads, chest): thrive on heavy work (5–10 reps) plus moderate volume.
- Type I leaning (calves, forearms): higher reps (12–20+), shorter rests, more frequency.
- Blend rep ranges weekly to cover the spectrum.
Practical plan
- One heavy day (4–8 reps), one pump day (12–20 reps) per muscle weekly.
- Track performance to see which rep ranges move fastest for you.