IGF1 and sarcopenia: Similarly, subgroup analysis revealed that exercise intervention could effectively improve serum IGF-1 levels in older adult individuals with frailty (SMD = 0.53, 95%CI: 0.07–0.98, I2 = 0%) or sarcopenia (SMD = 0.40, 95%CI: 0.19–0.61, I2 = 25%), with no statistically significant difference in effect sizes between the two groups.