Table 3.
Summary of articles in brain connectivity in older adults
| First author, year | Research design | n | Sex (% female) | Age, mean (S.D.) | Exercise mode | Exercise dose | Exercise min/week | Control/comparison group | Brain connectivity outcomes | Main findings |
|---|---|---|---|---|---|---|---|---|---|---|
| Smith, 2013 | Open trial | 35 | 71.4 | 76 (7.3) | Aerobic, walking | 12 weeks, 4×/week, 30 min, 50-60% | 120 min/week | Aerobic active control | Whole-brain activation | ↑ Efficiency of neural networks |
| Burdette, 2010 | Trial | 11 | 75 | 77.6 (5.0) | Aerobic (walking or other aerobic) | 16 weeks, 5×/week, 12-14 RPE | 150 min/week | Education and light stretching | Resting brain (hippocampus) blood flow and connectivity |
↑ Hippocampal connectivity ↑ Interconnectivity hippocampi and ACC |
| Colcombe, 2004 | Open trial | 29 | 62 | 65.6 (5.66) | Aerobic, walking | 26 weeks, 3×/week, 10-15 to 40-45 min, 40-50 to 60-70% THR | 45-135 min/week | Stretching and tone | Cerebral area activation in a cognitive task); GM density | ↑ Attentional circuitry in the MFG, SFG, and SPL and ↓ ACC activation |
| Voss, 2010 | RCT | 97 | 73 | 65.37 | Aerobic, walking | 52 weeks, 3×/week, 10-40 min, 50-60 to 60-75% THR | 30-120 min/week | Stretching and toning group and young control | Plasticity of brain networks |
↑ Connectivity in areas relevant to age-related cognitive decline ↑ Connectivity between areas within the DMN and within the FE (aerobic at 1 year) ↑ Connectivity between areas within the DMN (6 months) and within the FE (1 year) control group |
| Voelcker-Rehage, 2011 | RCT | 44 | 63.6 | 69.64 (3.84) | G1: aerobic, walking, G2: coordination | 52 weeks, 3×/week, 35-50 min, individual HR intensity zone, AerTGE (but below AnTG | 105-150 min/week | Relaxation and stretching | Brain activation patterns |
Both aerobic and coordination ↑ neural efficiency in the PFC Aerobic group: ↓ Activation of lsFG, MFG, bilateral mFG, the left ACC, the left parahippocampal gyrus, rtSTG, and mTP Coordination group: ↑ activation of iFG, sPC, thalamus, and caudate |
n = number of subjects; S.D. = standard deviation; RCT = randomized controlled trials; NR = not reported; NA = not applied; THR = target heart rate; RPE = rate of perceived exertion; 1RM = one-repetition maximum; ACC = anterior cingulate cortex; MFG = middle frontal gyrus; SFG = superior frontal gyrus; SPL = superior parietal lobules; DMN = default mode network; FE = frontal executive network; PFC = prefrontal cortex; lsFG = left superior frontal gyrus; bilateral mFG = bilateral middle frontal gyrus; rtSTG = right superior temporal gyrus; mTG = middle temporal gyrus; iFG = inferior frontal gyrus; sPC = superior parietal cortex; ↑ = significant increase; ↓ significant decrease