This assessor-blind randomized controlled clinical trial was aimed to compare the effects and brain mechanisms of aerobic plus resistance training (AR) versus calisthenics training (CT) on cognitive task-switching performances in middle-aged and older adults with MetS.
Among the 45 enrolled participants, 23 were originally assigned to the AR group and 22 to the CT group. Of these, 21 AR (64.7 ± 7.4 years) and 18 CT (64.7 ± 6.8 years) participants completed the 12-week triweekly training. Outcome measures included cardiorespiratory fitness, a modified Numerical Stroop test for examining task-switching performance, and brain functional activation (measured as blood oxygen level-dependent (BOLD) magnitude) while performing the modified Numerical Stroop test. These measures were collected at pre-training and post-training assessments. Completer analyses were performed. Group differences in changes in outcome measures were compared. Partial correlations between changes in fitness and brain activation BOLD magnitude with changes in task-switching performances were examined for each group.
There were no between-group differences in demographics and baseline data (p > 0.05). Both groups showed high program compliance (AR: 96.4%, CT: 95.1%), significant improvements in cardiorespiratory fitness (p 0.05), and significant correlations between improved submaximal exercise parameters (ventilatory threshold oxygen uptake and heart rate) and reduced task-switching reaction time (r = -0.524 － -0.715, p 0.05). For the AR group, individuals exhibiting greater increases in BOLD magnitude over the left middle frontal gyrus (MFG) activation demonstrated greater reductions in task-switching reaction time (r = -0.715, p = 0.002). In contrast, for the CT group, those with greater reductions in BOLD magnitude over bilateral MFG, left precuneus, and left angular gyrus showed greater reductions in task-switching errors (r = 0.649 － 0.704, p 0.05).
Both AR and CT exercises can assist individuals with MetS in improving cardiorespiratory fitness, which, in turn, was positively related to enhanced task-switching performance. However, the neural mechanisms underlying exercise-improved task-switching performance seemed different between these two types of exercises. While the cognitive effects of AR exercise may be associated with enhanced effective left MFG activation, those of CT exercise may be associated with relaxation and a reduction of redundant brain activation over bilateral MFG and posterior parietal association cortices.
The findings suggest that individuals with MetS may benefit from different exercise modalities for cognitive improvement. Further research is necessary to identify the optimal exercise strategies tailored to individual needs, promoting brain health and cognitive functions in this population.
cardiorespiratory fitness
cognitive task-switching
