A computational model proposes that titin kinase functions as a metastable mechanosensitive switch in skeletal muscle, where high-load resistance exercise induces stronger and longer-lasting signaling compared to endurance exercise due to force-dependent conformational changes, potentially explaining differential hypertrophic responses to training types.

When you lift heavy weights, the muscle fibers stretch a special protein called titin, which flips open a switch inside it. This switch turns on a chain of signals that tells the cell to make more machines (ribosomes) that build muscle proteins. Because the switch stays open longer under heavy loads, more machines are made over time, leading to bigger muscles. Lighter, endurance-style exercise doesn’t stretch the protein enough to keep the switch open long, so fewer machines are made and muscles don’t grow as much.