IGF1 and sarcopenia: Compared with previous studies that mostly focused on healthy middle-aged and older adult people and specific intervention methods, given that older adult populations with frailty and/or sarcopenia may have pathological bases such as chronic inflammation, hormonal imbalances, and abnormal muscle metabolism, with exercise’s IGF-1 regulatory mechanisms potentially differing from those in healthy populations, this study is the first to conduct a meta-analysis targeting older adult populations with frailty and/or sarcopenia.