TABLE 1.

Inclusion and exclusion criteria. At each stage of the research analysis for inclusion review, papers were included and excluded according to the above criteria.

Stage	Stage description	Inclusion criteria	Exclusion criteria
Ⅰ	Journal title analysis	Keywords: exercise, chronic exercise, physical activity, aging, skeletal muscle, autophagy, protein, gene	① Keywords: human, younger age, review, myocardial, brain, liver cells, tissues (other than skeletal muscle); ② Languages other than English or Chinese; ③ Human model; ④ Aging animals and cell culture models (other than skeletal muscle); ⑤Review or methods paper; ⑥Abstract or full-test is unavailable; ⑦ Not original study; ⑧ Missing data; ⑨ Proteins or genes outside the range.
Ⅱ	Abstract analysis	①Skeletal muscle tissue; ②Animal or cell model; ③Autophagy signaling activation; ④Chronic exercise.
Ⅲ	Full text analysis	①Skeletal muscle tissue; ②Animal or cell model; ③Autophagy signaling activation; ④Chronic exercise; ⑤Proteins include any one of the following: LC3, AMPK, Atg5/7/9/12, IGF-1, mTOR, FoxO3, Beclin1, Bcl-2, p62, PGC-1α.

Note: LC3, microtubule-associated protein-1 lightchain 3; AMPK, adenosine monophosphate-activated protein kinase; Atg, autophagy-related; mTOR, mammalian target of rapamycin; IGF-1, Insulin-like Growth Factors 1; Bcl-2, B-cell lymphoma 2; PGC-1α, peroxisome proliferator-activated receptor γ coactivator1-α.