Table 1 Characteristics and main findings of core neuroimaging and physical activity studies of older adults
| Study | Age range | Number | Type of exercise | Structures/processes investigated | Significant findings |
|---|---|---|---|---|---|
| Colcombe et al. (2004) [33] | 58–74 | 41 | Aerobic / stretching and toning | Prefrontal and parietal cortices, spatial selection and inhibitory functioning | Highly fit or aerobically trained individuals showed greater task-related activity in prefrontal and parietal cortices, which are involved in spatial selection and inhibitory functioning. |
| Colcombe et al. (2006) [52] | 60–79 | 59 | Aerobic / toning and stretching | Brain volume | Aerobic exercise increased brain volume in both gray and white matter regions. |
| Voss et al. (2010) [35] | 55–80 | 120 | Aerobic fitness level | Functional connectivity, executive function | Aerobic exercise was associated with functional connectivity on the default mode network, with processing speed and memory. |
| Erickson et al. (2010) [43] | 55–80 | 120 | Aerobic / stretching | Hippocampus, spatial memory | Aerobic exercise increased the size of the anterior hippocampus, BDNF serum levels, and improved spatial memory. |
| Liu-Ambrose et al. (2010) [57] | 65–75 | 155 | Resistance / balance and toning | Brain volume, executive function | Resistance exercise improved executive function and reduced brain volume to a greater extent than balance and tone exercises. |
| Voelcker-Rehage et al. (2011) [60] | 62–79 | 44 | Cardiovascular and coordination training / relaxation and stretching | Activity in prefrontal areas, executive functioning, perceptual speed | Cardiovascular and coordination training improved executive functioning and perceptual speed and decreased activation in prefrontal areas. |
| Ruscheweyh et al. (2011) [45] | 50–72 | 62 | Aerobic | Serum levels of granulocyte colony stimulating factor (G-CSF), brain-derived neurotrophic factor (BDNF), catecholamines (serum analyses), MRI, and episodic memory | Aerobic activity was associated with increases in local gray matter volume in prefrontal and cingulate cortex, and BDNF levels, and with enhanced memory. |
| Niemann et al. (2014) [51] | 62–79 | 70 | Cardiovascular and motor fitness / coordination training / stretching and relaxation | Volume of the basal ganglia, executive function and processing speed | Motor fitness (and not cardiovascular fitness) was related to the volume of the putamen and the globus pallidus. Motor fitness and coordination training was related to the volume of basal ganglia nuclei and to executive function tasks. |
| Eggenberger et al. (2016) [65] | 68–82 | 33 | Cognitive-motor video game dancing (exergame) / balance and stretching training | Prefrontal cortex activity, executive function | Dancing led to a larger reduction in left prefrontal cortex activity than balance and stretching, associated with improved executive functions. |
| Niemann et al. (2016) [69] | 65–82 | 57 | Aerobic / dancing | Gray matter brain volume, executive function | No differences in gray matter volume between dancing and other aerobic exercises. |
| Schättin et al. (2016) [66] | 72–87 | 27 | Cognitive exercises through exergames (videogames) / Conventional balance training, balance, motor | Prefrontal cortex activity, executive function | Exergame activity was associated with improved cognitive functioning and with greater prefrontal theta activity than classic balance exercises. |
| Rehfeld et al. (2017) [68] | 65–71 | 26 | Dancing / endurance strength and flexibility training | Volumes of hippocampal subfields and balance abilities | Left hippocampal volume increased in both groups but only the dancers showed increases in the left dentate gyrus and the right subiculum, as well as in the balance tests. |
| Jonason et al. (2017) [50] | 64–78 | 60 | Aerobic, stretching and toning | Cortical thickness in frontal regions, hippocampus volume, episodic memory, processing speed, updating, executive function | Aerobic activity, compared to other types of exercise, was associated with increased hippocampus volume and better cognitive functioning. |
| Müller et al. (2017) [67] | 63–80 | 22 | Dance / strength-endurance and flexibility training | Gray matter volume, short- and long-term verbal memory, auditory verbal learning test, attention tests | Increased gray matter volume in the left precentral gyrus in dancers than in controls. Similar results were obtained in both groups on the attention and memory tests. |
| Ji et al. (2017) [25] | 60–80 | 24 | Wii-fitness exercise that involves aerobic, balance, weight lifting, and yoga |
Multi-modal imaging measures Memory and executive function | Exercise reduced losses in several brain structures, notably the right striatum and the posterior cingulate, and improved memory and executive functions. |
| Håkansson et al. (2017) [49] | 50–79 | 19 | Physical exercise / cognitive training / mindfulness | BDNF serum levels | Physical exercise increased BDNF serum levels to a greater extent than cognitive training or mindfulness. |
| Godde et al. (2017) [61] | 63–79 | 43 | Walking / motor coordination / relaxation and stretching exercises | Brain activation | Walking and coordination exercises reduced right dorsolateral prefrontal cortex activation. |