The more total weight you lift over time—how heavy it is, how many times, and how many sets—the more your muscles grow, and even small differences in total lifting add up to small differences in...
Mechanism
Synthesis from 3 studies
Doing lots of reps with lighter weights makes your muscle cells fill up with more fluid and energy-making proteins, which makes the muscle look bigger—even if the actual muscle fibers don't get stronger. This happens because the repeated contractions trigger a chemical signal that tells the cell to...
Most probable mechanism
When you do many repetitions with lighter weights, your muscle cells get flooded with calcium each time they contract. This calcium triggers a chain reaction inside the cell that tells it to make more of certain non-muscle proteins, like those involved in energy production and fluid storage. Over time, these extra proteins make the muscle look bigger, even if the actual muscle fibers don't grow much.
Repeated high-repetition muscle contractions increase intracellular calcium flux in muscle fibers
Elevated intracellular calcium transiently activates MAPK signaling pathways (e.g., ERK1/2)
Activated MAPK signaling upregulates translational machinery for non-myofibrillar proteins (e.g., metabolic enzymes, sarcoplasmic proteins)
Increased synthesis of non-myofibrillar proteins leads to accumulation of sarcoplasmic components without proportional myofibrillar growth
Evidence from Studies
Supporting (1)
Community contributions welcome
Effects of High-Volume Versus High-Load Resistance Training on Skeletal Muscle Growth and Molecular Adaptations
Contradicting (2)
Community contributions welcome
Investigating the Effect of the Tonal Drop Set Mode On Elbow Flexor Hypertrophy
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.