Assessment of the Relationship Between Executive Function and Cardiorespiratory Fitness in Healthy Older Adults

Cardiorespiratory fitness is associated with cognitive function in late adulthood: baseline findings from the IGNITE study

OBJECTIVES

To evaluate the association between cardiorespiratory fitness (CRF) and cognition in a large sample of older adults, and to examine clinical and demographic factors that might moderate these associations.

METHODS

CRF was measured with a graded exercise test performed on a motorised treadmill. A confirmatory factor analysis was conducted using data from a comprehensive neuropsychological battery to obtain latent factors reflecting core cognitive domains. Linear regression models evaluated the association between CRF and each of the cognitive composites, and potential moderators including demographic factors (age, sex, education), apolipoprotein E ε4 (APOE4) carriage, beta-blocker use and components of maximal effort criteria during CRF testing.

RESULTS

The sample consisted of 648 adults (mean (SD) age 69.88 (3.75)), including 461 women (71.1%). The highest oxygen consumption obtained during testing (VO2max) was mean (SD) = 21.68 (5.06) mL/kg/min. We derived a five-factor model composed of episodic memory, processing speed, working memory, executive function/attentional control and visuospatial function. Higher CRF was associated with better performance across all five cognitive domains after controlling for covariates. Age and APOE4 carriage did not moderate observed associations. The relationship between CRF and cognitive performance was greater in women, those with fewer years of education and those taking beta-blockers in the domains of processing speed (sex: β=-0.447; p=0.015; education: β=-0.863; p=0.018) and executive function/attentional control (sex: β=-0.417; p=0.022; education β=-0.759; p=0.034; beta-blocker use: β=0.305; p=0.047).

CONCLUSION

Higher CRF in older adulthood is associated with better cognitive performance across multiple domains susceptible to age-related cognitive decline. Sex, education and use of beta-blockers moderated observed associations within select cognitive domains.

A Pre-Post Study Design Exploring the Potential Benefits of a Hiking Intervention for Active and Inactive Older Adults

INTRODUCTION

Physical activity (PA) is essential for healthy aging, yet PA levels are low in older adults. Group-based nature programming may be an ideal opportunity for engaging older adults in PA and improving health-related quality of life.

METHODS

Twenty-seven older adults, 55-75 years of age (n = 14 active and n = 13 previously inactive), enrolled in a biweekly 8-week hiking program. At baseline, participants completed online questionnaires on health-related quality of life, behavioral and psychological outcomes, and a one-mile walk test to assess cardiorespiratory fitness.

RESULTS

Average attendance was 81% in the previously inactive groups and 74% in the active group. There was a significant increase in the physical component of quality of life over time in the previously inactive group (p = .03, d = 0.71). Participants significantly improved their cardiorespiratory fitness (p = .003, d = 0.77) and competency (p = .005, d = 0.41) as assessed by the Basic Psychological Needs for Exercise Scale. The previously inactive group additionally increased their self-efficacy for exercise (p = .001, d = 1.43). Both active and previously inactive groups exercised at a similar relative intensity during the hikes based on heart rate; however, perceived exertion at the end of the hike on average was lower among active participants (p = .014).

CONCLUSION

Group-based hiking for previously inactive older adults significantly improved physical health-related quality of life over an 8-week biweekly intervention. Hiking at an individualized pace may allow for hiking to be an appropriate PA program in previously inactive older adults.

Impact of physical fitness and lifelong education on mild cognitive impairment in older adults

PURPOSE

The aim of this study was to explore the relationships among physical fitness, formal education levels, social educational experiences, and mild cognitive impairment in older adults.

METHODS

Using the Korean version of the mini-mental state examination, senior fitness tests, and questionnaires on social educational experiences and physical activity, the study assessed data on 148 Korean participants 65 years and above. Multiple linear regression analysis was conducted to examine the relationships among the factors.

RESULTS

The average age of the participants was 79.54 ± 0.55 years. Educational level showed a significant negative relationship with cognitive function scores, explaining 17.7% of the variance (R² = 0.177, p < 0.001). Current social educational experiences were significantly associated with a lower prevalence of mild cognitive impairment. Those without current social educational experiences were 1.946 times more likely to have MCI (p < 0.05) than those with such experiences. Physical fitness components, such as right upper body strength (OR = 1.171, 95% CI: 1.001-1.370), agility (OR = 1.246, 95% CI: 0.961-1.616), and cardiorespiratory fitness (OR = 0.975, 95% CI: 0.950-0.999), were also significantly associated with cognitive function. Additionally, older adult men had a higher likelihood of MCI than older adult women did (OR = 0.276, 95% CI: 0.097-0.782).

CONCLUSION

The findings highlight the importance of education, ongoing social educational experiences, and physical fitness in maintaining cognitive health in older adults. Thus, promoting lifelong education and physical fitness programs may help reduce the risk of mild cognitive impairment in older adults.

Associations that Cardiorespiratory Fitness and Body Mass Index Loss Have with Deficit Accumulation Frailty

INTRODUCTION/PURPOSE

Lower cardiorespiratory fitness and obesity may accelerate aging processes. The degree to which changes in fitness and body mass index (BMI) may alter the rate of aging may be important for planning treatment. We assessed cross-sectional and longitudinal associations that cardiorespiratory fitness and BMI had with a deficit accumulation frailty index (FI).

METHODS

Fitness, based on standardized graded exercise tests, and weight to calculate BMI at baseline and year 4 were collected from 3944 participants aged 45-76 yr in the Action for Health in Diabetes (Look AHEAD) randomized controlled clinical trial. A validated 38-item deficit accumulation FI was used as a marker of aging. Associations between baseline and changes in fitness and BMI with changes in FI were assessed using linear models.

RESULTS

Both baseline and 4-yr changes in fitness and BMI were independently associated with 4-yr changes in frailty (all P < 0.001). Mean (95% confidence interval) changes in FI ranged from -0.019 (-0.024, -0.013) for participants in the group with the greatest fitness increase and BMI loss to 0.029 (0.024, 0.034) for participants in the group with the greatest fitness loss and BMI gain. Associations of 4-yr changes in fitness and BMI with FI changes were similar across subgroups based on age, sex, baseline BMI, diabetes duration, and cardiovascular disease history. Increased fitness across 4 yr was associated with less FI accumulation independent of baseline fitness.

CONCLUSIONS

Adults with type 2 diabetes and overweight or obesity may slow aging processes captured by an FI by increasing their cardiorespiratory fitness and losing weight.

Functional Training and Dual-Task Training Improve the Executive Function of Older Women

Functional training (FT) is a type of multicomponent training with emphasis on activities of daily living that stimulate different physical capacities in only one session. Dual-task training (DTT) is a type of training that simultaneously applies cognitive and motor stimuli. We investigated the effects of sixteen weeks of FT and DTT and eight weeks of detraining on older women's inhibitory control, working memory, and cognitive flexibility. Sixty-two older women (66.9 ± 5.4 years; 27.7 ± 3.9 kg/m2) completed a 16-week intervention program comprising the FT (n = 31) and DTT (n = 31), and 43 returned after the detraining period. We used the Stroop Color Word Color test to evaluate inhibitory control, the Corsi Block Test to assess working memory, and the Trail Making Test to evaluate cognitive flexibility. Only DTT reduced the congruent response time between the pre-test and post-test (d= -0.64; p < 0.001), with no difference between the post-test and the detraining values (d = 1.13; p < 0.001). Both groups reduced the incongruent response time between the pre-test and post-test (FT: d = -0.61; p = 0.002; DTT: d= -0.59; p = 0.002) without a difference between groups. There were no significant differences in working memory and cognitive flexibility. Sixteen weeks of FT and DTT increased the inhibitory control of older women but not the working memory and cognitive flexibility, and these effects persisted after eight weeks of detraining.

Cardiorespiratory Fitness Moderates the Age-Related Association Between Executive Functioning and Mobility: Evidence From Remote Assessments

Background and Objectives

In older adults, executive functions are important for daily-life function and mobility. Evidence suggests that the relationship between cognition and mobility is dynamic and could vary according to individual factors, but whether cardiorespiratory fitness reduces the age-related increase of interdependence between mobility and cognition remains unexplored.

Research Design and Methods

One hundred eighty-nine participants (aged 50-87) were divided into 3 groups according to their age: middle-aged (MA; <65), young older adults (YOA; 65-74), and old older adults (OOA; ≥75). Participants performed Timed Up and Go and executive functioning assessments (Oral Trail Making Test and Phonologic verbal fluency) remotely by videoconference. Participants completed the Matthews questionnaire to estimate their cardiorespiratory fitness (VO2 max in ml/min/kg). A 3-way moderation was used to address whether cardiorespiratory fitness interacts with age to moderate the relationship between cognition and mobility.

Results

Results showed that the cardiorespiratory fitness × age interaction moderated the association between executive functioning and mobility (β = -0.05; p = .048; R2 = 17.6; p < .001). At lower levels of physical fitness (<19.16 ml/min/kg), executive functioning significantly influenced YOA's mobility (β = -0.48, p = .004) and to a greater extent OOA's mobility (β = -0.96, p = .002).

Discussion and Implications

Our results support the idea of a dynamic relationship between mobility and executive functioning during aging and suggest that physical fitness could play a significant role in reducing their interdependency.