The Claim
After three weeks of Nordic hamstring exercise training, motor unit discharge rates in the biceps femoris long-head increase by 6%, and this adaptation plateaus by nine weeks, indicating an early neural contribution to strength gains that diminishes over time.
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.
Performing Nordic hamstring exercises for three weeks leads to a 6% increase in the rate at which nerve signals activate the biceps femoris muscle, but this increase stops after nine weeks, suggesting that initial strength improvements are driven by nervous system changes that become less influential over time.
See the scientific wording
After three weeks of Nordic hamstring exercise training, motor unit discharge rates in the biceps femoris long-head increase by 6%, but this adaptation plateaus by nine weeks, indicating an early neural contribution to strength gains that diminishes over time.
When you first start doing Nordic hamstring exercises, your nerves send stronger and more frequent signals to your hamstring muscle, making it contract harder right away. After a few weeks, the nerves stop sending even more signals, but the muscle itself starts to change physically — it gets longer and more resilient — so it can still produce more force without needing extra nerve input.
What the research says
1 studyIn the first three weeks of Nordic hamstring training, your nerves start firing more often to make your hamstring stronger, but after nine weeks, they stop increasing their firing rate—your muscles instead get physically stronger on their own.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.