Baseline levels of circulating senescence-associated secretory phenotype (SASP) proteins are associated with the magnitude of improvement in physical function following a 12-week exercise program in older adults.

Before exercise begins, higher levels of certain inflammatory proteins in the blood indicate that more cells in the body are stuck in a damaged, non-functioning state. These proteins make tissues less able to respond to the signals that exercise sends to repair and strengthen them. When exercise happens, it reduces the number of these damaged cells and lowers the levels of those inflammatory proteins. People who start with more of these proteins have more damage to fix, so their bodies show bigger improvements after exercise because they have more room to recover.