How Slow-Twitch Muscle Fibers Boost Strength and Endurance If you’ve ever taken a Lagree class at Studio Physique in St. Petersburg, you’ve heard your trainer say it: “Find the shake!” That shake isn’t just effort — it’s your slow-twitch muscle fibers firing and working to their limit. These small but mighty fibers are the secret behind Lagree’s long, lean, sculpted results. Let’s break down why they matter — and how every class on the Megaformer helps strengthen them. Fast-Twitch vs. Slow-Twitch Muscle Fibers Your muscles are made of two main fiber types: Fast-twitch (Type II)• Built