Greater motor unit discharge rate during rapid contractions in strength-trained individuals
Author Information
Author(s): Škarabot Jakob, Casolo Andrea, Balshaw Thomas G., Maeo Sumiaki, Lanza Marcel Bahia, Holobar Aleš, Farina Dario, Folland Jonathan P., Del Vecchio Alessandro
Primary Institution: Loughborough University
Hypothesis
Strength-trained individuals will exhibit a greater initial motor unit discharge rate during rapid contractions compared to untrained individuals.
Conclusion
Strength-trained individuals have a higher maximal motor unit discharge rate during rapid contractions, but this does not lead to a greater relative rate of force development compared to untrained individuals.
Supporting Evidence
- Strength-trained individuals produced greater absolute forces during rapid contractions compared to untrained individuals.
- Initial motor unit discharge rates were significantly higher in strength-trained individuals for both biceps brachii and vastus lateralis.
- Despite higher motor unit discharge rates, relative rates of force development did not differ between groups.
Takeaway
People who train their muscles a lot can make their muscles work faster, but it doesn't mean they can push harder compared to those who don't train.
Methodology
The study compared motor unit discharge characteristics and rate of force development during rapid contractions in strength-trained and untrained individuals using high-density electromyography.
Potential Biases
Potential bias due to the non-uniform strength training backgrounds of participants.
Limitations
The study's cross-sectional design limits the ability to determine causality, and the variability in strength training programs among participants may have influenced results.
Participant Demographics
Participants included 13 strength-trained and 12 untrained men for elbow flexors, and 11 strength-trained and 10 untrained men for knee extensors, aged 18-40 years.
Statistical Information
P-Value
p<0.0001
Confidence Interval
[68, 80]
Statistical Significance
p<0.0001
Digital Object Identifier (DOI)
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