The Claim
Nordic hamstring exercise training increases the torque at which motor units are de-recruited by 12% after nine weeks of training, but does not produce a significant change after three weeks, indicating a time-dependent adaptation in motor unit termination behavior.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
After nine weeks of Nordic hamstring exercises, the force required to stop muscle fibers from firing increases by 12%, but no change is seen after three weeks, suggesting that the nervous system's control of muscle activation adapts slowly over time.
See the scientific wording
Nordic hamstring exercise training increases the torque at which motor units are de-recruited by 12% after nine weeks, but not after three weeks, suggesting a delayed adaptation in motor unit termination behavior.
After repeated eccentric training, the hamstring muscle fibers grow longer and add more contractile units in series, which changes how the muscle stretches and sends signals back to the spinal cord. These altered signals make the motor neurons keep firing longer as the muscle relaxes, so they stay active at higher force levels before turning off. This change takes time because it depends on physical remodeling of the muscle, not just faster nerve signals.
What the research says
1 studyAfter doing Nordic hamstring exercises for nine weeks, the muscles learned to stay active at higher levels of force before turning off — but this didn’t happen after just three weeks. It’s like your muscles needed more time to learn a new trick.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
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