Why Do Muscles Shake During Pilates? The Science Behind It
Ever Wondered Why Your Muscles Shake During Pilates? Here’s The Science-Backed Reason!
If you’ve ever experienced that unmistakable, uncontrollable muscle shake mid-way through a Pilates class, you’re not alone. Whether it’s during a slow Teaser or a steady Plank, muscle shaking is one of the most common (and celebrated) signs of progress. But what’s actually happening inside your body?
Spoiler alert: It’s not weakness. It’s GROWTH.
Why Do Muscles Shake During Pilates?
The shaking comes down to muscle fatigue, nervous system overload, and motor unit recruitment. When you’re holding a move (like a plank) for an extended time or working through controlled, precise movements, your body is calling on motor units (a motor neuron + muscle fibers) to fire. As the smaller, endurance-based units fatigue, your body recruits bigger, more powerful motor units to keep you going. This "switching" causes small fluctuations in force, which we experience as "the shakes."
5 Science-Backed Reasons Why Muscles Shake During Pilates
Muscle Fatigue
Pilates focuses on endurance-based, controlled movements. As slow-twitch muscle fibers (built for endurance) tire, fast-twitch fibers (built for power) are recruited to help.
This "switch" creates a temporary imbalance, causing the shakes.
Motor Unit Switching
The nervous system rotates motor units to maintain force. As smaller motor units (primarily slow-twitch) tire, larger units (fast-twitch) kick in to sustain movement.
This swap isn’t seamless — the transition causes instability, and we feel this as muscle shaking.
Stabilizer Muscles Are Fatiguing
Deep stabilizers like the transversus abdominis and multifidus are small but mighty.
Pilates targets these stabilizers, especially during exercises like leg lifts or side-lying work, causing early fatigue and shakes.
Post-Injury Effects
Clients recovering from injury (especially back and neck injuries) experience more muscle shaking because stabilizer muscles around the injury site are weaker.
The nervous system also works harder post-injury to "retrain" muscle control and proprioception, leading to increased muscle shakes.
Autonomic Nervous System Activation
When your body is under physical stress (like during intense Pilates work), the sympathetic nervous system (fight or flight) is activated.
This heightened state makes motor units hyper-responsive, increasing the likelihood of shaking.
Why Do People With Back or Neck Injuries Shake More?
Weaker stabilizing muscles: After injury, muscles like the transversus abdominis and multifidus often become weak or "deactivated."
Protective Muscle Guarding: The body’s larger muscles (like the erector spinae) compensate for weakened stabilizers, and they fatigue faster.
Proprioception Reboot: The nervous system is "relearning" how to stabilize the spine, and this retraining process often leads to shakiness.
How To Support Clients During Muscle Shakes
Normalize It: Let them know it’s a sign of strength, not weakness.
Rest If Needed: Encourage them to take a pause, especially post-injury.
Modify the Exercise: Reduce range, duration, or load if the shakes become overwhelming.
Key Takeaway: If you’re shaking, you’re growing. Embrace it!
