When the total amount and intensity of workout effort are kept the same, performing more than one type of isolation exercise for each muscle group does not lead to greater muscle growth.
Mechanism
Synthesis from 1 study
If you lift the same total weight and push just as hard, it doesn’t matter if you switch exercises—your muscles still get the same amount of stress and burn, so they grow the same. Adding more exercises doesn’t give them anything new to respond to.
Most probable mechanism
When you do the same total amount of work and push just as hard, your muscles get the same amount of pulling and burning sensation no matter which exercises you use. This means all the muscle fibers get stimulated the same way, so they all grow the same amount.
Total mechanical tension applied to muscle fibers is equivalent across training protocols when volume and intensity are held constant.
Metabolic stress (accumulation of metabolites like lactate and hydrogen ions) is similarly induced across exercise variations under matched volume and intensity.
Muscle fiber recruitment patterns and time-under-tension are not significantly altered by exercise variety when total workload is unchanged.
Equivalent levels of mechanical tension and metabolic stress lead to similar activation of mTOR signaling and protein synthesis pathways in muscle tissue.
Evidence from Studies
Supporting (1)
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Muscle Hypertrophy and Strength Adaptations to Systematically Varying Resistance Exercises
Contradicting (0)
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Gold Standard Evidence Needed
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