Table 1 Characteristics of the included studies

Van Uffelen et al. 2008 [32]

75.10

n = 138

walking (moderate-intensity) vs. non-aerobic group exercises (low-intensity)

60 min, 2 times/week, 1 year

MMSE, AVLT, DSST, SCWT-A, BDNF (biospecimen collection)

Barha et al. 2017 [36]

73.84

n = 58

walking (HRR:60–70%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 6 months

MMSE, MoCA, ADAS-Cog, TMT B-A, Stroop Test, 6MWT, BDNF (biospecimen collection)

Nagamatsu et al. 2013 [33]

74 .89

n = 49

walking (HRR:40–80%) vs. balance and tone (unspecified intensity)

60 min, 2 times/week, 6 months

RAVLT, spatial memory

Dao et al. 2017 [37]

71.73

n = 22

walking (HRR:60–70%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 6 months

ADAS-Cog, TMT, Stroop Test, DSST, physiological profile assessment, Amyloid-β imaging (MRI)

Tao et al. 2019 [41]

65.55

n = 37

walking (HRR:55–75%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 24 weeks

MoCA, hippocampal volume (MRI)

Ten Brinke et al. 2015 [34]

75.78

n = 21

walking (HRR:40–80%) vs. usual care (unspecified intensity)

60 min, 2 times/week, 6 months

RAVLT, hippocampal volume (MRI)

Tarumi et al. 2019 [42]

64.72

n = 45

walking (HRR:75–90%) vs. stretching exercises (HRR: < 50%)

25–40 min, 3–5 times/week, 12 months

CVLT-II, D-KEFS, global brain and hippocampal volumes, mean cortical and precuneus Aβ plaque deposition (Amyloid PET)

Tomoto et al. 2021 [43]

64.70

n = 37

walking (HRR:75–90%) vs. stretching and toning exercises (HRR: < 50%)

25–40 min, 3–5 times/week, 12 months

CVLT-II, D-KEFS, cerebral blood flow velocity, mean arterial pressure, cerebral vasomotor reactivity

Hsu et al. 2018 [39]

73.03

n = 21

walking (HRR:60–70%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 6 month

MMSE, MoCA, 6MWT, cerebral cortex activity

Liu-Ambrose et al. 2016 [35]

74.25

n = 58

walking (HRR:60–70%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 6 month

ADAS-Cog, Stroop Test, TMT, 6MWT, EXIT-25, ADCS-ADL

Hsu et al. 2017 [38]

71.1

n = 21

walking (HRR:60–70%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 6 month

6MWT, Timed-Up-and-Go Test, Short Physical Performance Battery, physical activities scale for the elderly, cerebral cortex activity

Ten Brinke et al. 2018 [40]

72.39

n = 28

walking (HRR:60–70%) vs. usual care and health education (unspecified intensity)

60 min, 3 times/week, 6 month

Stroop Test, TMT, DSST, 6MWT, cerebral cortex activity

Tomoto et al. 2021 [45]

65.45

n = 37

walking (HRR:75–90%) vs. stretching and toning exercises (HRR: < 50%)

25–40 min, 3–5 times/week, 12 months

MMSE, CVLT-II, D-KEFS, cardiovascular hemodynamics, cerebrovascular hemodynamics, brain tissue volume, white matter hyperintensity, cardiorespiratory fitness

Liu et al. 2021 [44]

65.15

n = 37

walking (HRR:55–75%) vs. original physical activity levels and health education (unspecified intensity)

MoCA, cortical functional connectivity (fMRI)