Do different types of lifting change muscle signals differently?
Effect of different muscle contraction mode on the expression of Myostatin, IGF-1, and PGC-1 alpha family members in human Vastus Lateralis muscle
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
No statistically significant difference in PGC-1α-4 increase between eccentric and concentric exercise, despite different IGF-1 isoforms being activated.
Most fitness experts claim eccentric training is superior for hypertrophy — but this study shows the core growth signal (PGC-1α-4) is identical in both.
Practical Takeaways
Focus on controlled, full-range movements in your lifts — whether you're pushing up or lowering down, you're activating the same core muscle growth pathway.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
No statistically significant difference in PGC-1α-4 increase between eccentric and concentric exercise, despite different IGF-1 isoforms being activated.
Most fitness experts claim eccentric training is superior for hypertrophy — but this study shows the core growth signal (PGC-1α-4) is identical in both.
Practical Takeaways
Focus on controlled, full-range movements in your lifts — whether you're pushing up or lowering down, you're activating the same core muscle growth pathway.
Publication
Journal
Molecular Biology Reports
Year
2020
Authors
Pejman Taghibeikzadehbadr, S. Shirian, Mostafa Sabouri
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Claims (6)
When muscles are strongly activated during physical exercise, the body produces more insulin-like growth factor 1 (IGF-1), a protein involved in tissue growth and repair.
A single workout using concentric knee extensions raises the activity of specific muscle genes (PGC-1α-1, PGC-1α-4, IGF-1Ea, IGF-1Eb), while a single workout using eccentric knee extensions raises different but partially overlapping genes (PGC-1α-4 and IGF-1Ec), showing that the type of muscle contraction influences which genes are activated.
After one session of knee extension exercises—whether lowering or lifting the weight—there is no measurable change in the levels of myostatin mRNA in the thigh muscle of healthy young men, when tested right after the workout.
After resistance exercise, human muscle activates different versions of the IGF-1 and PGC-1α genes depending on whether the movement is concentric or eccentric, suggesting that mechanical stress triggers distinct molecular signals.
After a single session of weight training, human muscle cells show a temporary increase in proteins that promote muscle growth and energy production, but do not show a change in a protein that limits muscle growth.