Greater habitual moderate-to-vigorous physical activity is associated with better executive function and higher prefrontal oxygenation in older adults

Moderate intensity intermittent lifestyle physical activity is associated with better executive function in older adults

Executive functions are among the first cognitive abilities to decline with age and age-related executive function slowing predisposes older adults to cognitive disorders and disease. Intermittent Lifestyle Physical Activity (ILPA) reflects brief, unplanned activity that occurs during routine daily activities and is operationalized as activity bouts <60s. Our understanding of short bouts of habitual physical activity and executive functions is limited. We tested the hypothesis that greater amounts of ILPA in moderate and vigorous intensity domains would be associated with better executive function in older adults. Forty older adults (26 females, 68 ± 6, >55 years; body mass index: 26.6 ± 4.3 kg/m2) completed a Trail-Making-Task and wore an activPAL 24-hr/day for 6.2 ± 1.8-days. For each intensity, total time and time spent in bouts <60 s were determined. Trail A (processing speed) and Trail B (cognitive flexibility) were completed in 25.8 ± 8.2 s and 63.2 ± 26.2 s, respectively. Non-parametric Spearman's rank correlations report that moderate ILPA (3.2 ± 3.2 min/day) and total-moderate physical activity (20.1 ± 16.0 min/day) were associated with faster Trail A (total-moderate physical activity: ρ=-0.48; moderate-ILPA: ρ = -0.50; both, p < 0.003) and Trail B time (total-moderate physical activity: ρ = 0.36; moderate-ILPA: ρ = -0.46; both, p < 0.020). However, the results show no evidence of an association with either vigorous physical activity or light physical activity (total time or ILPA bouts: all, p > 0.180). Moderate physical activity accumulated in longer bouts (>60 s) was not associated with Trail B time (p = 0.201). Therefore, more total moderate physical activity and shorter bouts (<60 s) may result in better executive functions in older adults.

Association between changes in habitual stepping activity and cognition in older adults

Advancing age is associated with declines in cognitive function. Although physical activity is thought to protect against this decline, it is unclear how a short-term uptake in daily steps or a decline in day-to-day step variability may contribute to cognition among older adults. We tested associations between changes in step counts, day-to-day step variability and executive cognitive functions among older adults taking part in a physical activity intervention. Thirty-seven older adults (33 females; 71.4 ± 6.3 years) completed a 10-week personalized physical activity intervention. Participants wore a Fitbit to measure daily step counts throughout the study. They also completed a computerized Stroop task before and after the intervention. Average step counts and step count variability via average-real-variability (ARV) were determined. Compared to pre-intervention, step counts increased (p < 0.001) and step variability decreased post-intervention (p = 0.04). Models describing the changes in step counts and ARV over the 10-weeks were cubic (both, p < 0.04). Reaction times during the simple (p = 0.002) and switching (p = 0.04) conditions were faster post-intervention. Change in step variability was positively associated with the change in reaction time for the switching condition (β = 0.029, p = 0.002). On average, a reduction in day-to-day step variability was associated with improvements in cognitive flexibility.

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.

Frailty is associated with worse executive function and higher cerebral blood velocity in cognitively healthy older adults: a cross-sectional study

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: β=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (β=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (β=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.

Mild exercise improves executive function with increasing neural efficiency in the prefrontal cortex of older adults

This study examined whether a 3-month mild-exercise intervention could improve executive function in healthy middle-aged and older adults in a randomized control trial. Ultimately, a total of 81 middle-aged and older adults were randomly assigned to either an exercise group or a control group. The exercise group received 3 months of mild cycle exercise intervention (3 sessions/week, 30-50 min/session). The control group was asked to behave as usual for the intervention period. Before and after the intervention, participants did color-word matching Stroop tasks (CWST), and Stroop interference (SI)-related reaction time (RT) was assessed as an indicator of executive function. During the CWST, prefrontal activation was monitored using functional near-infrared spectroscopy (fNIRS). SI-related oxy-Hb changes and SI-related neural efficiency (NE) scores were assessed to examine the underlying neural mechanism of the exercise intervention. Although the mild-exercise intervention significantly decreased SI-related RT, there were no significant effects of exercise intervention on SI-related oxy-Hb changes or SI-related NE scores in prefrontal subregions. Lastly, changes in the effects of mild exercise on NE with advancing age were examined. The 81 participants were divided into two subgroups (younger-aged subgroup [YA], older-aged subgroup [OA], based on median age [68 years.]). Interestingly, SI-related RT significantly decreased, and SI-related NE scores in all ROIs of the prefrontal cortex significantly increased only in the OA subgroup. These results reveal that a long-term intervention of very light-intensity exercise has a positive effect on executive function especially in older adults, possibly by increasing neural efficiency in the prefrontal cortex.

Examining sex differences in the association between sedentary behavior and cognitive function in bariatric surgery patients

BACKGROUND

Obesity is associated with cognitive impairment. A potential contributor to these deficits is sedentary behavior (SB), which is linked to poorer cognitive functioning in other populations. Little is known about the association between SB and cognitive function in bariatric surgery populations.

OBJECTIVES

This cross-sectional study examined the association between SB and cognitive function in preoperative bariatric surgery patients, as well as possible sex differences in this relationship.

SETTING

Data were collected at 2 health centers in the United States.

METHODS

A total of 121 participants (43.2 ± 10.3 yr of age) scheduled for Roux-en-Y gastric bypass or sleeve gastrectomy completed the National Institute of Health (NIH) Toolbox for the Assessment of Neurological and Behavioral Function Cognition Domain, a computerized neuropsychological assessment battery. Participants wore a waist-mounted accelerometer for 7 consecutive days to measure SB and light-intensity physical activity (LPA).

RESULTS

Pearson and partial correlations found no significant relationships between cognitive function and SB or LPA in the full sample. However, partial correlations controlling for LPA found that greater SB was associated with poorer performance on List Sorting Working Memory Test in women (r = -.28; P = .006), whereas there was a positive relationship between SB and Dimensional Change Card Sort for men (r = .51; P = .015; 95% CI [.25, .73]).

CONCLUSIONS

These results showed that greater SB, independent of LPA, is associated with poorer working memory in women and better set shifting ability in men. Future studies should examine the possibility of domain-specific cognitive effects associated with SB in bariatric surgery samples and clarify possible sex differences.

Short-Form Video Exposure and Its Two-Sided Effect on the Physical Activity of Older Community Women in China: Secondary Data Analysis

Background

There is a tendency for older adults to become more physically inactive, especially older women. Physical inactivity has been exacerbated since the COVID-19 pandemic. Lockdowns and information-based preventive measures for COVID-19 increased the number of short-form video app users and short-form video exposure, including content exposure and the duration of exposure, which has demonstrated important effects on youths' health and health-related behaviors. Despite more older adults viewing short-form videos, less is known about the status of their short-form video exposure or the impacts of the exposure on their physical activity.

Objective

This study aims to describe physical activity-related content exposure among older adults and to quantify its impacts along with the duration of short-form video exposure on step counts, low-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA).

Methods

We analyzed a subsample (N=476) of older women who used smartphones and installed short-form video apps, using the baseline data collected from an ongoing cohort study named the Physical Activity and Health in Older Women Study (PAHIOWS) launched from March to June 2021 in Yantai, Shandong Province, China. The information on short-form video exposure was collected by unstructured questions; physical activity-related content exposure was finalized by professionals using the Q-methodology, and the duration of exposure was transformed into hours per day. Step counts, LPA, and MVPA were assessed with ActiGraph wGT3X-BT accelerometers. Multiple subjective and objective covariates were assessed. Linear regression models were used to test the effects of short-form video exposure on step counts, LPA, and MVPA. MVPA was dichotomized into less than 150 minutes per week and 150 minutes or more per week, and the binary logistic regression model was run to test the effects of short-form video exposure on the achievement of spending 150 minutes or more on MVPA.

Results

Of 476 older women (mean age 64.63, SD 2.90 years), 23.7% (113/476) were exposed to physical activity-related short-form videos, and their daily exposure to short-form videos was 1.5 hours. Physical activity-related content exposure increased the minutes spent on MVPA by older women (B=4.14, 95% CI 0.13-8.15); the longer duration of short-form video exposure was associated with a reduced step count (B=-322.58, 95% CI -500.24 to -144.92) and minutes engaged in LPA (B=-6.95, 95% CI -12.19 to -1.71) and MVPA (B=-1.56, 95% CI -2.82 to -0.29). Neither content exposure nor the duration of exposure significantly increased or decreased the odds of older women engaging in MVPA for 150 minutes or more per week.

Conclusions

Short-form video exposure has both positive and negative impacts on the physical activity of older adults. Efforts are needed to develop strategies to leverage the benefits while avoiding the harms of short-form videos.

Interrupting bedtime to reverse frailty levels in acute care: a study protocol for the Breaking Bad Rest randomized controlled trial

BACKGROUND

Hospitalized older patients spend most of the waking hours in bed, even if they can walk independently. Excessive bedrest contributes to the development of frailty and worse hospital outcomes. We describe the study protocol for the Breaking Bad Rest Study, a randomized clinical trial aimed to promoting more movement in acute care using a novel device-based approach that could mitigate the impact of too much bedrest on frailty.

METHODS

Fifty patients in a geriatric unit will be randomized into an intervention or usual care control group. Both groups will be equipped with an activPAL (a measure of posture) and StepWatch (a measure of step counts) to wear throughout their entire hospital stay to capture their physical activity levels and posture. Frailty will be assessed via a multi-item questionnaire assessing health deficits at admission, weekly for the first month, then monthly thereafter, and at 1-month post-discharge. Secondary measures including geriatric assessments, cognitive function, falls, and hospital re-admissions will be assessed. Mixed models for repeated measures will determine whether daily activity differed between groups, changed over the course of their hospital stay, and impacted frailty levels.

DISCUSSION

This randomized clinical trial will add to the evidence base on addressing frailty in older adults in acute care settings through a devices-based movement intervention. The findings of this trial may inform guidelines for limiting time spent sedentary or in bed during a patient's stay in geriatric units, with the intention of scaling up this study model to other acute care sites if successful.

TRIAL REGISTRATION

The protocol has been registered at clinicaltrials.gov (identifier: NCT03682523).

Alternations of vitamin D and cognitive function in first-diagnosed and drug-naïve BD patients: Physical activity as a moderator

BACKGROUND

The pathophysiological mechanism of cognitive impairments of bipolar disorder (BD) has not yet been completely revealed. It is well known that Vitamin D and physical activity (PA) are associated with BD. However, specific links between Vitamin D and cognitive deficits in BD are still unclear.

METHOD

The serum levels of vitamin D were measured. The cognitive performances of 102 first-diagnosed and drug-naïve BD patients were evaluated for analysis. The repeatable battery for the assessment of neuropsychological status (RBANS) and the Stroop Color-Word test was used in this study. PA was collected by international physical activity questionnaire.

RESULT

Patients with BD had high levels of serum vitamin D. Furthermore, immediate and delayed memory was negatively associated with vitamin D levels in patients' group. The serum levels of vitamin D in patients with low PA were positively associated with memory. However, increased PA attenuated the protective effect of vitamin D on executive cognition.

CONCLUSION

It is concluded that the increased levels of vitamin D were observed in the serum of patients with BD. Thus, it is found that more PA is less beneficial to cognition of patients with BD than longer resting.

The effects of an exercise intervention on executive function among overweight adults with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is associated with poorer executive function. This study examined the effects of a comprehensive exercise intervention on executive function in overweight adults with mild and moderate-to-severe OSA.

METHODS

Participants aged between 30 and 65 years, with a body mass index (BMI) ranging from 27 to 42 kg/m^2, participated in a 6-week exercise program. Standardized polysomnographic recording methods provided total Apnea-Hypopnea Index (AHI) and level of hypoxemia. Executive function was assessed using the NIH Toolbox Flanker Inhibitory Control Test. A submaximal treadmill exercise test evaluated cardiorespiratory fitness. Participants with baseline total AHI between 5 and 14.9 events/h were classified as mild OSA and participants with baseline total AHI 15 ≥ events/h were classified as moderate-to-severe OSA.

RESULTS

Fifteen participants completed 18 exercise sessions. Significant differences between OSA categories at baseline were observed for sleep characteristics, but not for fitness or executive function. Wilcoxon Signed Rank Tests showed significant increases in median values for the Flanker Test in the moderate-to-severe category only, z = 2.429, p < .015, η² = .737.

CONCLUSION

Six weeks of exercise improved executive function in overweight individuals with moderate-to-severe OSA, but not in those with mild OSA.

Objective physical activity accumulation and brain volume in older adults: An MRI and whole brain volume study

A decrease in brain volume (i.e., brain atrophy) is a marker of cognitive health in older adults. Insufficient weekly accumulation of moderate and vigorous physical activity (MVPA) has been associated with lower brain volume. As this association has been established for a small number of brain areas and structures and atrophy rates seem to be nonuniform between them, more comprehensive analyses are warranted. We compared the volume of 71 brain areas and structures in 45 older adults who met and did not meet objectively measured MVPA recommendations. In addition, we used multiple regression models to determine whether cardiorespiratory fitness (VO2PEAK), MVPA and health-related risk factors could affect the atrophy of brain areas and structures. An accelerometer (GT9-X ActiGraph®) was worn for 7 days. Participants were then classified into two groups: <150 minutes MVPA (< 150'MVPA) (n=20) and ≥150 minutes MVPA (≥ 150'MVPA) (n=25) per week. Older adults who accumulated ≥ 150'MVPA per week had significantly higher absolute and relative (% of intracranial volume) volumes of 39 and 9 brain areas and structures, respectively, than those who accumulated < 150'MVPA per week. Higher VO2PEAK seems to be a key predictor of the atrophy of brain areas and structures. In conclusion, meeting weekly physical activity recommendations seems to have a widespread effect on preserving the volume of more than 30 brain areas and structures in older adults. VO2PEAK seems to be the most frequent and important predictor of brain volume preservation.

Effects of Group-Play Moderate to Vigorous Intensity Physical Activity Intervention on Executive Function and Motor Skills in 4- to 5-Year-Old Preschoolers: A Pilot Cluster Randomized Controlled Trial

The aim of the present study is to examine the effect of group-play intervention on executive function (EF) in preschoolers. This group-play intervention was integrated as moderate to vigorous physical activity and cognitively loaded exercise to promote EF in preschoolers. An 8-week group-play MVPA intervention program, consisting of a series of outdoor physical and cognitively loaded games, was designed to improve preschoolers' EF. This intervention program was implemented in group-play form, and conducted by teachers who received standardized training before the intervention. Two classes of second grade preschoolers (N = 62) were randomly allocated to experimental (n = 30, M age = 4.16, SD = 0.29) and control (n = 32, M age = 4.7, SD = 0.43) groups. The intervention group received the intervention three times a week, while the control group exercised as usual in preschool. Before, in the middle of, and after the intervention, 10-m running, standing broad jump, throwing, body flexion, balance beam, and skip jump were assessed as tests of motor skills. In addition, three components of EF were measured separately before, in the middle of, and after the intervention: inhibitory control was assessed by using the silly sound Stroop task, working memory was tested using the empty house task, and shifting was assessed using the dimensional change card sorting task. Although both groups showed an increasing trend in terms of motor skills and EF during the intervention, the increasing amounts of the intervention group were significantly higher than the control group. The findings of the present study suggested that group-play intervention has positive effects on aspects of EF in addition to motor skills in preschoolers.

A Cross-Sectional Study on Self-Perceived Health and Physical Activity Level in the Spanish Population

One-third of the Spanish population over 15 years of age did not achieve a reasonable amount of physical activity (PA) before the COVID-19 pandemic. We aim to analyse the associations between the PA level (PAL) and self-perceived health (SPH) in the Spanish population aged 15−69 years during the pre-pandemic period. A cross-sectional study was conducted using the Spanish National Health Survey 2017 (ENSE 2017) data, with 17,777 participants. We carried out a descriptive analysis, analysed intergroup differences with non-parametric statistical tests, and calculated the Odds Ratio (OR) and Relative Risk (RR) of having a negative SPH according to PAL. In addition, correlations between PAL and SPH were studied, finding associations between them (p < 0.001). Thus, performing moderate and intense PA was related to better SPH than just walking or inactive. Weak and moderate correlations were found between PAL and SPH (p < 0.001). We also found high ORs and RRs of negative SPH as PAL decreased. Moderate and intense PA were related to positive SPH, while the risk of negative perception in inactive people was higher.

Association between Accelerometer-Measured Light-Intensity Physical Activity and Cognitive Function in Older Adults

OBJECTIVES

This study aimed to investigate whether accelerometer-measured light physical activity (LPA) is associated with cognitive function and whether engaging in ≥3 h/day of LPA can reduce the chance of cognitive impairment among a sample of older adults in Taiwan.

DESIGN

Cross-sectional study.

SETTING

An outpatient department in a medical center.

PARTICIPANTS

Participants were community-dwelling older adults aged 65 years and older who were able to walk independently from September 2020 to March 2021.

MEASUREMENTS

A tri-axial accelerometer was used to measure LPA for 7 consecutive days, and the Mini-Mental State Examination (MMSE) scale was used to assess the chance of cognitive impairment. Multiple linear regression model and binary logistic regression model were performed to examine the association between LPA and MMSE scores.

RESULTS

145 older Taiwanese adults (51.7% men; 81.2±6.8 years; 6.9% at chance of cognitive impairment) were included. After adjusting for moderate-to-vigorous physical activity (MVPA) and wear time, we found that there was a significant association between LPA and cognitive function (95% confidence interval [CI]: 0.64-1.65; P<0.001), and further found that those who engaged in LPA ≥3 h/day were at reduced chance of cognitive impairment compared with people who engaged in LPA <3 h/day (odds ratio [OR]: 0.16; 95% CI: 0.03-0.80; P=0.025).

CONCLUSION

This study demonstrated that engaging in LPA ≥3 h/day could be viewed as a protective factor for maintaining cognitive function in older adults. We recommend further longitudinal research to elucidate the association between intensity-specific LPA and cognitive function.

The impact of different step rate threshold methods on physical activity intensity in older adults

BACKGROUND

Older adults benefit most from engaging in higher-intensity physical activity, which is often determined using step rate thresholds. Fixed step rate thresholds that correspond to moderate (MPA) and vigorous-intensity physical activity (VPA) have been developed for heuristic activity promotion. The activPAL monitor uses step rate thresholds to determine activity intensity. Stepping thresholds may also vary based on body mass index (BMI) or aerobic fitness level in older adults. Despite the various thresholds used in the literature, it is unclear whether they produce similar outcomes.

RESEARCH QUESTION

How does time spent in physical activity intensities compare between different step rate thresholds in older adults?

METHODS

Thirty-eight participants (24♀; 67 ± 4 years; BMI: 26.6 ± 4.4 kg/m²) wore an activPAL monitor 24-hr/day for up to 7-d (total: 205-d). Aerobic fitness (V̇O₂max: 23 ± 8 ml/kg/min) was determined via indirect calorimetry during a maximal, graded cycling test. Time spent in each intensity category (light-physical-activity [LPA], MPA, VPA) was determined using the fixed (MPA/VPA) 100/130, 110/130, and activPAL step rate thresholds (74/212), as well as BMI-adjusted absolute (108.5 ± 2.5/134.0 ± 4.8) and BMI-adjusted relative (40%/60% V̇O₂max; 111.4 ± 14.7/132.0 ± 19.0) cut-offs. Times spent in each intensity category were compared between methods.

RESULTS

The activPAL and 100/130 thresholds yielded less LPA and more MPA than all other methods. The activPAL had no time spent in VPA at all. The BMI-adjusted absolute and relative thresholds produced statistically equivalent time in LPA and MPA (via equivalence testing), but not VPA. No two methods yielded similar time spent in LPA, MPA, or VPA.

SIGNIFICANCE

The choice of step rate threshold has a major impact on physical activity intensity outcomes in older adults. Inherently, strategies that adjust for older adults' body size and/or aerobic fitness level provide a more individualized data processing strategy than fixed thresholds that assume the same threshold for all older adults.

Leg Fidgeting Improves Executive Function following Prolonged Sitting with a Typical Western Meal: A Randomized, Controlled Cross-Over Trial

Prolonged uninterrupted sitting and a typical Western meal, high in fat and refined sugar, can additively impair cognitive and cerebrovascular functions. However, it is unknown whether interrupting these behaviours, with a simple desk-based activity, can attenuate the impairment. The aim of this study was to determine whether regular leg fidgeting can off-set the detrimental effects of prolonged sitting following the consumption of a typical Western meal, on executive and cerebrovascular function. Using a randomized cross-over design, 13 healthy males consumed a Western meal and completed 180-min of prolonged sitting with leg fidgeting of 1 min on/4 min off (intervention [INT]) and without (control [CON]). Cognitive function was assessed pre and post sitting using the Trail Maker Test (TMT) parts A and B. Common carotid artery (CCA) blood flow, as an index of brain flow, was measured pre and post, and cerebral (FP1) perfusion was measured continuously. For TMT B the CON trial significantly increased (worsened) completion time (mean difference [MD] = 5.2 s, d = 0.38), the number of errors (MD = 3.33, d = 0.68) and cognitive fatigue (MD = 0.73, d = 0.92). Compared to CON, the INT trial significantly improved completion time (MD = 2.3 s, d = 0.97), and prevented declines in cognitive fatigue and a reduction in the number of errors. No significant changes in cerebral perfusion or CCA blood flow were found. Leg fidgeting for 1-min on/4-min off following a meal high in fats and refined sugars attenuated the impairment in executive function. This attenuation in executive function may not be caused by alterations in CCA blood flow or cerebral perfusion.

Cardiorespiratory fitness and prefrontal cortex oxygenation during Stroop task in older males

AIM

The aim of the current study was to assess whether executive function and prefrontal oxygenation are dependent on fitness level and age in older adults.

METHODS

Twenty-four healthy males aged between 55 and 69 years old were recruited for this study. They were stratified by age, leading to the creation of two groups: 55-60 years old and 61-69 years old. A median split based on CRF created higher- and lower-fit categories of participants. Cerebral oxygenation was assessed using functional near-infrared spectroscopy (fNIRS) during a computerized Stroop task. Accuracy (% of correct responses) and reaction times (ms) were used as behavioural indicators of cognitive performances. Changes in oxygenated (∆[HbO2]) and deoxygenated (∆[HHb]) hemoglobin were measured to capture neural changes. Repeated measures ANOVAs (CRF × Age × Stroop conditions) were performed to test the null hypothesis of an absence of interaction between CRF, Age and executive performance.

RESULTS

We also found an interaction between CRF and age on reaction times (p = .001), in which higher fitness levels were related to faster reaction times in the 61-69 year olds but not in the 55-60 year olds. Regarding ΔHHb, the ANOVA revealed a main effect of CRF in the right PFC (p = .04), in which higher-fit participants had a greater Δ[HHb] than the lower-fit (d = 1.5). We also found fitness by age interaction for Δ[HHb] in the right PFC (p = .04).

CONCLUSION

Our results support the positive association of CRF on cerebral oxygenation and Stroop performance in healthy older males. They indicated that high-fit individuals performed better in the 61-69 year olds group, but not in the 55-60 years old group. We also observed a greater PFC oxygenation change (as measured by Δ[HHb]) in the high-fit individuals.