Previous research in young adults has demonstrated that both motor learning and transcranial direct current stimulation (tDCS) trigger decreases in the levels of gamma-aminobutyric acid (GABA) in the sensorimotor cortex, and these decreases are linked to greater learning. Less is known about the role of GABA in motor learning in healthy older adults, a knowledge gap that is surprising given the established aging-related reductions in sensorimotor GABA. Here, we examined the effects of motor learning and subsequent tDCS on sensorimotor GABA levels and resting-state functional connectivity in the brains of healthy older participants. Thirty-six older men and women completed a motor sequence learning task before receiving anodal or sham tDCS to the sensorimotor cortex. GABA-edited magnetic resonance spectroscopy of the sensorimotor cortex and resting-state (RS) functional magnetic resonance imaging data were acquired before and after learning/stimulation. At the group level, neither learning nor anodal tDCS significantly modulated GABA levels or RS connectivity among task-relevant regions. However, changes in GABA levels from the baseline to post-learning session were significantly related to motor learning magnitude, age, and baseline GABA. Moreover, the change in functional connectivity between task-relevant regions, including bilateral motor cortices, was correlated with
Background
With a rapidly ageing society, healthy ageing has become a key challenge. Engagement in physical activity, and particularly walking, is a key strategy that contributes to healthy ageing amongst older adults. The purpose of the present study was to evaluate the efficacy of a group walking program for older adults that incorporates the 5R Shared Leadership Program (5RS). By implementing a structure of shared leadership and strengthening peer leaders’ identity leadership, 5RS aims to cultivate a shared social identity amongst participants, which has in other contexts been associated with greater performance and well-being.
Methods
A cluster randomised controlled trial was conducted to test the efficacy of the 5RS group walking program on group identification, group cohesion, walking activity, and well-being, compared to a regular group walking program for older adults. Nineteen older adult walking groups (i.e., the clusters; N = 503; Mage = 69.23 years, SD = 6.68) all participated in a 12-week structured group walking program. Nine walking groups (n = 304) were randomly assigned to the intervention in which participants received the 5RS program in addition to regular group walking.
Results
5RS was successful in strengthening the identity leadership qualities of the appointed peer leaders. Multilevel regressions showed that 5RS succeeded in increasing group cohesion and walking activity to a greater extent than a regular group walking program, while participants’ group identification and well-being increased to a similar extent in both conditions. Furthermore, structural equation modelling revealed that group identification mediated the impact of peer leaders’ identity leadership on group cohesion and well-being (but not walking activity).
Conclusion
By harnessing the capacity of the group and its peer leaders, the 5RS program offers a promising intervention to engage older adults in physical activity.
Trial registration
The study was retrospectively registered as clinical trial on 9 September 2021 (NCT05038423).
Aims
Type 2 diabetes mellitus (T2DM) is associated with reduced exercise capacity and cardiovascular diseases, both increasing morbidity and risk for premature death. As exercise intolerance often relates to cardiac dysfunction, it remains to be elucidated to what extent such an interplay occurs in T2DM patients without overt cardiovascular diseases. Design: Cross-sectional study, NCT03299790.
Methods and results
Fifty-three T2DM patients underwent exercise echocardiography (semi-supine bicycle) with combined ergospirometry. Cardiac output (CO), left ventricular longitudinal strain (LS), oxygen uptake (O2), and oxygen (O2) extraction were assessed simultaneously at rest, low-intensity exercise, and high-intensity exercise. Glycaemic control and lipid profile were assessed in the fasted state. Participants were assigned according to their exercise capacity being adequate or impaired (EXadequate: O2peak <80% and EXimpaired: O2peak ≥80% of predicted O2peak) to compare O2 extraction, CO, and LS at all stages. Thirty-eight participants (EXimpaired: n = 20 and EXadequate: n = 18) were included in the analyses. Groups were similar regarding HbA1c, age, and sex (P > 0.05). At rest, CO was similar in the EXimpaired group vs. EXadequate group (5.1 ± 1 L/min vs. 4.6 ± 1.4 L/min, P > 0.05) and increased equally during exercise. EXimpaired patients displayed a 30.7% smaller increase in O2 extraction during exercise compared to the EXadequate group (P = 0.016) which resulted in a lower O2 extraction at high-intensity exercise (12.5 ± 2.8 mL/dL vs. 15.3 ± 3.9 mL/dL, P = 0.012). Left ventricular longitudinal strain was similar at rest but increased significantly less in the EXimpaired vs. EXadequate patients (1.9 ± 2.5% vs. 5.9 ± 4.1%, P = 0.004).
Conclusions
In asymptomatic T2DM patients, an impaired exercise capacity is associated with an impaired response in oxygen extraction and myocardial deformation (LS).
Trial registry
Effect of High-intensity Interval Training on Cardiac Function and Regulation of Glycemic Control in Diabetic Cardiomyopathy (https://clinicaltrials.gov/ct2/show/NCT03299790).
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