Table 3.
Intervention characteristics and outcomes of included human studies
| Author | Type of exercise training | Duration of exercise intervention | Duration of each training session | Frequency of exercise training | Intensity of exercise training | Outcomes (cognitive tests) | Main cognitive results | Effect size | |
|---|---|---|---|---|---|---|---|---|---|
| Endurance exercise training | Leischik et al. [82] | Walking | 12 weeks | 40 min | 3x/week | ? | Cognitive attention/performance (FAIR-Test 2), verbal memory, non-verbal memory | Verbal memory, nonverbal memory, and cognitive performance significantly improved in the walking group and E-health group compared to the control group |
Cognitive performance: Walking vs. control: d = 0.73 E-health vs. control: d = 1.15 Quality value: Walking vs. control: d = 0.34 E-health vs. control: d = 0.41 Continuity value: Walking vs. control: d = 0.63 E-health vs. control: d = 1.05 Verbal memory: Walking vs. control: d = 0.73 E-health vs. control: d = 1.70 Non-verbal memory: Walking vs. control: d = 6.57 E-health vs. control: d = 6.32 |
| Ploydang et al. [83] | Aquatic Nordic walking | 12 weeks | 60 min | 3x/week |
First 6 weeks: 40–50% HRR Last 6 weeks: 50–60% HRR |
Visuospatial/executive function, naming, memory, attention, language, abstraction, delayed recall, and orientation (MoCA), orientation to time, orientation to place, registration, attention and calculation, word recall, language, and visual construction (MMSE), executive function (TMT part B), inhibition (Stroop colour and word test) | Significantly increased MoCA scores in Nordic walking group. No significant improvements in MMSE, Stroop test, or TMT |
MoCA: d = 0.46 MMSE: d = 0.05 Stroop: d = 0.12 TMT B: d = 0.03 |
|
| Wang et al. [84] | Outdoor aerobic dancing | 1 year | 60 min | 3x/week | ? | Cognitive screening (MMSE) + cognitive impairment (MoCA) | Aerobic training group had significantly increased MMSE and MoCA scores compared to the control group |
MMSE: d = 0.58 MoCA: d = 0.55 |
|
| Liu et al. [97] | Walking | 3 months | 50 min | 3x/week |
moderate intensity: 40–59% HRR |
Executive function (dimensional change card sort test) Episodic memory (picture sequence memory test) Working memory (List sorting working memory test) Processing speed (Pattern Comparison Processing Speed Test) |
Non-significant increases in executive function, episodic memory, working memory and processing speed scores |
Executive function: η2 = 0.027 Episodic memory: η2 = 0.013 Working memory: η2 = 0.008 Processing speed: η2 = 0.045 |
|
| Resistance exercise training | Zhao et al. [85] |
Whole-body, machine based power training (3 sets of 8 reps of lateral pulldown, chest press, upper back, leg press, knee extension, and knee flexion, hip extension and hip abduction) |
12 months | ? | 3 days/week |
High intensity (15–18 on Borg scale, 80% 1RM) |
Memory (word list memory, word list recall, and word list recognition subtests of the Consortium to Establish a Registry for Alzheimer’s Disease), attention/speed (TMT Part A (Trails A)), executive function: (TMT Part B (Trails B) + Trail Making Test B minus A (Trails B minus A)), global cognitive function (MMSE) | Cognition of both groups improved over time, with increased scores in the Trails A, Trails B, word list recall, and word list memory |
MMSE: d = − 0.52 TMT A: d = 0.10 TMT B: d = 0.16 TMT B – TMT A: d = 0.31 Word list memory: d = − 0.04 Word list recall: d = 0.32 Word list recognition: d = 0.00 |
| Yamamoto et al. [86] |
Body weight resistance training + exercises with elastic bands: tube fly, front raise, hammer curl, leg extension, calf raise, and squat Performed 20 times each |
48 weeks | ? | Daily | ? | Cognitive function (MMSE) | No significant changes in MMSE score | MMSE: d = 0.59 | |
| Endurance vs resistance exercise training | Teixeira et al. [87] |
Endurance exercise: elliptical, bike, treadmill, or upper-body cycle ergometer Resistance exercise |
12 weeks | 40 min | 3x/week |
Endurance: 60% HRmax resistance: 11–12 Borg scale |
MTTS: attention and concentration(cognitrone), reaction time (determination test), selective attention (visual pursuit test) |
The group with both T2DM and hypertension showed a significantly increased number of reactions, but no significantly improved reaction time. No differences were observed between the endurance and resistance exercise group |
/ |
| Combined endurance and resistance exercise training | Silveira-Rodrigues et al. [88] |
6 resistance exercises (reverse grip lat pulldown, leg press, bench press machine, calf raises machine, dumbbell shoulder press, and abdominal crunches) + 15 min of treadmill walking, with increasing weight and repetition number over 8 weeks |
8 weeks | ? | 3x/week |
week 1–2: 20 min at 100% v6MWT (aerobic) 2 × 13–15 MRs, i = 60 s (strength) week 3–4 20 min at 105% v6MWT (aerobic) 3 × 13–15 MRs, i = 60 s (strength) week 5–6 25 min at 105% v6MWT (aerobic) 3 × 10–12 MRs, i = 60 s (strength) week 7–8 25 min at 105–110% v6MWT (aerobic) 3 × 8–10 MRs, i = 60 s (strength) |
Cognitive screening (MoCA), visuospatial memory (Taylor's complex figure test), processing speed (TMT A), cognitive flexibility (TMT B), verbal fluency (semantic and alternate word fluency), processing speed (digit symbol substitution), working memory (digit span test), attention/concentration/inhibitory control (Stroop colour test) | Significantly improved inhibitory control, working memory, cognitive flexibility, and attention in the exercise group compared to the control group |
Memory: d = − 0.07 Verbal fluency: d = − 0.01 Processing speed: d = − 0.10 Attention/concentration: d = 0.64 Cognitive flexibility: d = 0.67 Inhibitory control: d = 0.89 Working memory: d = 0.88 |
| Espeland et al. [89] | Walking, resistance training, and flexibility exercises | 2 years | 50 min | 3–4x/week | Moderate intensity | Global cognitive function (3MSE), psychomotor speed, attention, and working memory (the Wechsler Adult Intelligence Scale-III DSC test), delayed recall (HVLT-D), processing speed and executive function (computer tests: 1-back and 2-back tasks, the Eriksen Flanker task, and a task-switching paradigm) | Global cognitive function and delayed memory, significantly improved only in T2DM patients who received training |
3MSE: d = 3.24 DSC: d = 1.50 HVLT-D: d = 3.24 Executive function: d = 0.69 |
|
| Silveira-Rodrigues et al. [90] |
6 resistance exercises (reverse grip lat pulldown, leg press, bench press machine, calf raises machine, dumbbell shoulder press, and abdominal crunches) + treadmill walking, with increasing weight and repetition number over 8 weeks |
8 weeks | 40–60 min | 3x/week |
week 1–2: 20 min at 100% v6MWT (aerobic) 2 × 13–15 MRs, i = 60 s (strength) week 3–4 20 min at 105% v6MWT (aerobic) 3 × 13–15 MRs, i = 60 s (strength) week 5–6 25 min at 105% v6MWT (aerobic) 3 × 10–12 MRs, i = 60 s (strength) week 7–8 25 min at 105–110% v6MWT (aerobic) 3 × 8–10 MRs, i = 60 s (strength) |
Executive function: cognitive flexibility (TMT), inhibitory control (Stroop Colour Task), working memory (Digit Span) Long-term memory: simplified Taylor Complex Figure Test |
Executive function was significantly improved in exercise group |
Executive function: d = 1.31 Inhibitory control: d = 0.87 Working memory: d = 0.40 Cognitive flexibility: d = 0.96 Long-term memory: d = 0.22 |
|
| Ghodrati et al. [91] | Combined training: endurance + resistance + balance exercises | 12 weeks | 65 min | 3x/week |
Endurance: 55–75% HRmax resistance: 65–85% 1RM |
Cognitive function (MoCA), information processing speed + overall cognitive functioning (DSST), short-term memory (forward digit span test) | Intervention group scored significantly higher on MoCA than control group, and increased score with 3.1 compared to baseline. No improvement in DSST or forward digit span test |
MoCA: d = 0.18 DSST: d = 0.05 Forward digit span: d = 0.16 |
|
| Martinez-Velilla et al. [92] |
Combination of resistance, balance, and walking exercises Squats rising from a chair, leg press, and bilateral knee extension, seated bench press semitandem foot standing, line walking, stepping practice, walking with small obstacles, proprioceptive exercises on unstable surfaces, altering the base of support, and weight transfer from one leg to the other, knee extension and flexion, hip abduction, walking along corridor |
8 days | 20 min |
2x/day 5–7 days/week |
? | MMSE | After the intervention, the exercise group scored on average 1.6 points higher than the control group (23.7 vs. 22.1), significant | MMSE: d = 0.69 | |
| Callisaya et al. [93] | Combination of endurance and resistance exercise | 6 months | 1 h | 3x/week |
Started at low to moderate, progressed to moderate to vigorous |
Cognitive function: Victoria Stroop test, TMT (shifting score B-A), the DSC Test, digit span subtest of the Wechsler Adult Intelligence Scale (third edition), Controlled Oral Word Association Test, three part HVLT-D (revised), Rey Complex Figure copy and delay | Better global cognitive score, better performance on the DSC Test, Rey Complex Copy test, Stroop C-D, Trail Making Test A and B, Hopkins intermediate and recognition, and Controlled Oral Word Association Test |
Cognitive global score: d = 2.43 RCF copy: d = 1.67 RCF delay: d = 0.5 Stroop C-D: d = − 2.84 Trails B-A: d = − 0.48 DSC: d = 1.77 Digit span: d = − 3.43 Hopkins I: d =− 0.53 Hopkins D: d = 0.6 Hopkins R: d = 2 COWAT word: d = 1.57 COWAT category: d = 0.84 |
|
| Ghahfarrokhi et al. [94] | Endurance exercises, upper and lower body strength, balance exercises and maintaining posture, and hip control exercises and mid-body stability | 6 weeks |
30–35 min (HIFT) 40–45 min (LIFT) |
3x/week (HIFT) 5x/week (LIFT) |
HIFT: 100–120% lactate threshold LIFT: 70–75% lactate threshold |
Cognitive screening (MMSE), processing speed (SDMT), learning (CVLT-II), memory (BVMT-R), attention (Stroop tests) | MMSE, Stroop, SDMT, CVLT-II and BVMT-R scores improved significantly in the HIFT group. MMSE and Stroop scores improved significantly in the LIFT group. Only change in Stroop scores in the HIFT group was significantly different from the control group |
MMSE: HIFT: d = 0.73 LIFT: d = 0.71 Control: d = − 0.09 Stroop: HIFT: d = 0.82 LIFT: d = 0.72 Control: d = − 0.24 SDMT: HIFT: d = 0.55 LIFT: d = 0.22 Control: d = 0.08 CVLT-II: HIFT: d = 0.61 LIFT: d = 0.42 Control: d = 0.06 BVMT-R: HIFT: d = 0.66 LIFT: d = 0.45 Control: d = − 0.15 |
|
| Other exercise types | Chen et al. [95] | 24-form simplified Tai Chi Chuan | 36 weeks | 60 min | 3x/week | Moderate intensity | Global cognition (MoCA), MQ, DSST, TMT-B, BNT, ROCFT |
Both interventions significantly increased MoCA scores, with a significantly larger effect of Tai Chi Chuan compared to fitness walking. 24 weeks: DSST score was more effectively improved by the Tai Chi Chuan group compared to the fitness walking group. No significant differences in MQ, TMT-B, BNT or ROCFT between Tai Chi Chuan and fitness walking group. MoCA, MQ, DSST, and TMT-B scores improved significantly more in Tai Chi Chuan group compared to control group. MoCA scores in fitness walking group improved significantly more than in control group 36 weeks: MQ scores improved significantly more in Tai Chi Chuan group compared to fitness walking group. MQ, DSST, and TMT-B scores improved significantly more in Tai Chi Chuan group compared to control group. MoCA scores in fitness walking group improved significantly more than in control group |
MoCA: Tai Chi Chuan vs. control: d = 0.63 Fitness walking vs. control: d = 0.33 Wechsler Memory Quotient (MQ): Tai Chi Chuan vs. control: d = 0.47 Fitness walking vs. control: d = 0.15 DSST: Tai Chi Chuan vs. control: d = 0.31 Fitness walking vs. control: d = 0.14 TMT B: Tai Chi Chuan vs. control: d = − 0.37 Fitness walking vs. control: d = − 0.06 BNT: Tai Chi Chuan vs. control: d = 0.21 Fitness walking vs. control: d = 0.16 ROCFT: Tai Chi Chuan vs. control: d = 0.07 Fitness walking vs. control: d = − 0.12 ROCFT delayed recall: Tai Chi Chuan vs. control: d = 0.01 Fitness walking vs. control: d = 0.00 |
| Cai et al. [96] | Kinect-based Kaimai-style Qigong | 12 weeks | 30 min | 3x/week | Low intensity | Cognitive function (MMSE) | Qigong group showed significant improvements in cognitive function compared to the control group | MMSE: d = 1.75 |
BNT Boston Naming Test, BVMT-R Brief Visuospatial Memory Test-Revised, CBS Cambridge Brain Sciences, CVLT-II California Verbal Learning Test II, d cohen’s d, DSC digit symbol coding, DSST Digit Symbol Substitution Test, HIFT High-Intensity low-volume Functional Training, HRmax Heart Rate maximum, HRR heart rate reserve, HVLT-D Hopkins Verbal Learning Test revised, I rest interval between sets and strength-type exercises, LIFT Low-Intensity High-volume Functional Training, MMSE Mini-Mental State Examination, MoCA Montreal Cognitive Assessment, MQ Weschler Memory Quotient, MRI Magnetic Resonance Imaging, MRs maximal repetitions, MTTS Mental Test and Training System, ROCFT Rey-Osterrieth Complex Figure Test, SDMT Symbol Digit Modalities test, TMT Trail Making Test, TUG timed up-and-go, V1 intervention midpoint, V2 postintervention, v6MWT velocity in 6 min walking test, ηp2 = partial eta-squared, 1RM = 1 Rep Maximum, 3MSE = Modified Mini Mental State Exam