Why some people gain muscle and others don’t — even with the same workout
Assessing differential responders and mean changes in muscle size, strength, and the cross-over effect to two distinct resistance training protocols.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Two different weightlifting routines made people stronger in the same way, but only one made their arm muscles thicker. One routine even made the other arm stronger without touching it.
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Systematic Reviews & Meta-Analyses
Max 100Randomized Controlled Trials
Max 90Cohort Studies
Max 72Case-Control Studies
Max 58Cross-Sectional Studies
Max 44Case Reports & Case Series
Max 30Expert Opinion & Narrative Reviews
Max 552 / 90
Evidence Score
Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Two different weightlifting routines made people stronger in the same way, but only one made their arm muscles thicker. One routine even made the other arm stronger without touching it.
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Systematic Reviews & Meta-Analyses
Max 100Randomized Controlled Trials
Max 90Cohort Studies
Max 72Case-Control Studies
Max 58Cross-Sectional Studies
Max 44Case Reports & Case Series
Max 30Expert Opinion & Narrative Reviews
Max 552 / 90
Evidence Score
Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.
Publication
Authors
Dankel SJ, Bell ZW, Spitz RW, Wong V, Viana RB, Chatakondi RN, Buckner SL, Jessee MB, Mattocks KT, Mouser JG, Abe T, Loenneke JP
Related Content
Claims (4)
Using heavy weights close to your maximum strength can increase strength in an arm that wasn't even trained, but lighter, traditional training does not produce this effect. This suggests that the intensity of the training, not just any resistance exercise, determines whether untrained limbs gain strength.
In a study comparing training methods, only the traditional training group showed consistent, measurable differences in strength gains, while changes in muscle size and strength in the non-trained arm were not reliably distinguishable from random measurement noise, suggesting some studies may incorrectly identify individuals as responders.
Two different weight training methods improved strength by about the same amount in healthy adults over six weeks, but only one method—doing four sets to exhaustion—also led to a measurable increase in muscle size.
People who have not previously trained respond with varying amounts of muscle growth depending on the type of resistance training they perform.