For people new to weight training, doing more resistance exercises per week is linked to greater muscle growth. For those already trained, increasing the volume of training does not consistently lead...
Mechanism
Synthesis from 1 study
When you first start lifting, your muscles respond strongly to the workout and grow fast. But after training for a while, they get used to the stress and don’t respond as much — so doing more workouts doesn’t make them grow any bigger.
Most probable mechanism
When someone first starts lifting weights, their muscles are very responsive to the stress and grow quickly. But after training for a while, the muscles become less sensitive to the same amount of stress, so adding more workouts doesn’t make them grow much more.
Mechanical tension from resistance training activates mTORC1 signaling pathways in muscle cells, promoting protein synthesis and muscle growth.
In previously trained individuals, repeated exposure to mechanical load reduces the sensitivity of mTORC1 signaling to further increases in training volume.
Reduced mTORC1 responsiveness leads to diminished rates of muscle protein synthesis despite higher training volumes, limiting further hypertrophy.
Less supported by current evidence, but not ruled out
Trained muscles already have a high baseline of protein building and breaking down, so extra workouts don’t tip the balance enough to add more muscle.
Trained muscle exhibits elevated basal rates of both protein synthesis and protein breakdown.
Training-induced increases in protein synthesis are smaller in magnitude and shorter in duration in trained individuals compared to untrained individuals.
The net balance between synthesis and breakdown remains near zero despite higher training volumes, limiting hypertrophic gains.
Evidence from Studies
Supporting (1)
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Contradicting (0)
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Gold Standard Evidence Needed
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