In highly trained people, using resistance training with either low or high amounts of fatigue loss for six weeks results in no difference in triceps muscle thickness, but the quadriceps muscle in...
Mechanism
Synthesis from 1 study
In people who lift weights regularly, training to more fatigue doesn't make the triceps grow bigger, but it can slightly increase the size of a thigh muscle. This is because the triceps are already used to heavy loads and don't need extra stress to grow, while the thigh muscle still has some room...
Most probable mechanism
When muscles are trained to near fatigue, they experience more stress and chemical changes that trigger growth, but not all muscles respond the same way — some, like the thigh muscle, grow a little more under higher fatigue, while others, like the triceps, don't change much no matter how much fatigue is applied, likely because they're already adapted to heavy loads.
Higher velocity loss during resistance exercise increases neuromuscular fatigue, requiring greater recruitment of high-threshold motor units to maintain force output.
Increased motor unit recruitment elevates mechanical tension and metabolic stress within muscle fibers, activating intracellular signaling pathways linked to protein synthesis.
Metabolic stress and mechanical tension stimulate mTORC1 and related anabolic pathways, increasing muscle protein synthesis rates.
Net protein accretion leads to increased muscle fiber cross-sectional area, but the magnitude of this response varies between muscles due to differences in fiber type composition, training history, and mechanical loading patterns.
Evidence from Studies
Supporting (1)
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Effects of Low- Versus High-Velocity-Loss Thresholds With Similar Training Volume on Maximal Strength and Hypertrophy in Highly Trained Individuals.
Contradicting (0)
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