Mechanical tension generated by muscle contraction activates the mTOR signaling pathway, resulting in increased muscle protein synthesis and skeletal muscle hypertrophy.

Study: Differential effects of resistance and endurance exercise in the fed state on signalling molecule phosphorylation and protein synthesis in human muscle

When you lift weights, your muscles get stronger and bigger because the tension from lifting turns on a molecular switch (mTOR) that tells your body to make more muscle proteins. This study showed that weightlifting does exactly that.

Study: Time-of-day effect of high-intensity muscle contraction on mTOR signaling and protein synthesis in mice

When muscles are squeezed hard, they turn on a molecular switch called mTOR that tells the body to make more muscle proteins — and this study saw that switch get flipped on during muscle contractions, even if the total protein made didn’t change at different times of day.

Study: Dual roles of mTOR in skeletal muscle adaptation: coordinating hypertrophic and mitochondrial biogenesis pathways for exercise-induced chronic disease management

When you lift weights and your muscles stretch and contract under tension, it turns on a molecular switch called mTOR, which tells your muscles to grow bigger by making more proteins. The study shows that when this switch is blocked, muscles don’t grow as much.