Effects of Detraining on Physical Capacity and Its Relationship With Depressive Symptoms, Quality of Life and Sedentary Behavior in Community-Dwelling Older Adults: A Longitudinal Study.

BACKGROUND: Detraining is the partial or complete loss of physical training-induced adaptations as a result of exercise interruption or reduction. The COVID-19 pandemic led to the discontinuation of many older adult exercise programs and led to increased depressive symptoms (DS), increased sedentary behavior (SB), and decreased quality of life (QoL). OBJECTIVE: To evaluate the effects of detraining, in the pandemic, on physical capacity and its relationship with DS, QoL, and SB of community-dwelling older adults. METHODS: The physical capacity (static balance, dynamic balance, and lower limb and handgrip strength) of 35 participants was assessed prepandemic and after 18 and 24 months of the pandemic. DS, QoL, and SB were evaluated only at 18-month period. The analysis of variance for repeated measures or the Friedman and Pearson or Spearman tests were used for statistical analysis. RESULTS: There was a decline in dynamic balance (p < .001) and strength in the lower limbs (p < .001) in the first 18 months, as well as maintenance in the following 6 months. The reduction in dynamic balance during the 18 months of the pandemic was associated with greater DS (p = .015; r = .414) and worse QoL (p = .024; r = -.381) in this period. More time spent on SB (p = .024; r = .386) in the 18th month was associated with worse dynamic balance in the following 6 months. CONCLUSION: Detraining in the pandemic setting led to long-lasting harmful effects, which can last for 2 years, on the physical capacity of community-dwelling older adults. IMPLICATION: Our findings highlight how periods of detraining can interfere in physical and mental health of older adults.

Changes of the cardiac baroreflex bandwidth during postural challenges.

Baroreflex is commonly typified from heart period (HP) and systolic arterial pressure (SAP) spontaneous variations in the frequency domain mainly by estimating its sensitivity. However, an informative parameter linked to the rapidity of the HP response to SAP changes, such as the baroreflex bandwidth, remains unquantified. We propose a model-based parametric approach for estimating the baroreflex bandwidth from the impulse response function (IRF) of the HP-SAP transfer function (TF). The approach accounts explicitly for the action of mechanisms modifying HP regardless of SAP changes. The method was tested during graded baroreceptor unloading induced by head-up tilt (HUT) at 15°, 30°, 45°, 60°, and 75° (T15, T30, T45, T60, and T75) in 17 healthy individuals (age: 21-36 yr; 9 females and 8 males) and during baroreceptor loading obtained via head-down tilt (HDT) at -25° in 13 healthy men (age: 41-71 yr). The bandwidth was estimated as the decay constant of the monoexponential IRF fitting. The method was robust because the monoexponential fitting described adequately the HP dynamics following an impulse of SAP. We observed that 1) baroreflex bandwidth is reduced during graded HUT and this narrowing is accompanied by the reduction of the bandwidth of mechanisms that modify HP regardless of SAP changes and 2) baroreflex bandwidth is not affected by HDT but that of SAP-unrelated mechanisms becomes wider. This study provides a method for estimating a baroreflex feature that provides different information compared with the more usual baroreflex sensitivity while accounting explicitly for the action of mechanisms changing HP irrespective of SAP.

Reproducibility of isokinetic measures of the knee and ankle muscle strength in community-dwelling older adults without and with Alzheimer's disease.

BACKGROUND: To interpret changes of muscle strength in older adults with Alzheimer's disease (AD), determining the reliability of outcome measures is necessary. Therefore, the purpose of the present study was to investigate the relative and absolute intra-rater reliability of concentric isokinetic measures of the knee and ankle muscle strength in community-dwelling older adults without and with AD in the mild and moderate stages. METHODS: A methodological study was conducted. The participants were submitted to two isokinetic evaluations with an interval of three to seven days. The evaluations consisted of knee extension and flexion at 60°/s (five repetitions) and 180°/s (15 repetitions) and plantar flexion and dorsiflexion of the ankle at 30°/s (five repetitions). The measures of interest were peak torque, average peak torque and total work. The intraclass correlation coefficient two-way mixed model of a single-measure (ICC3,1), standard error of measurement (SEM) and minimal detectable change at the 95% confidence interval (MDC95) were calculated. The ICC3,1 was interpreted based on Munro's classification. Standard error of measurement and MDC95 were analyzed in absolute and relative values (percentage of error [SEM%] and change [MDC95%]). RESULTS: A total of 62 older adults were included and allocated to the three groups: mild-AD (n = 22, 79.9 years, 15 female and seven male), moderate-AD (n = 20, 81.6 years, 15 female and five male) and without-AD (n = 20, 74.3 years, 10 female and seven male). The ICCs3,1 of the measures of knee were high/very high in the three groups (0.71-0.98). The ICCs3,1 of the measures of ankle were high/very high in the mild-AD group (0.78-0.92), moderate/high/very high in the moderate-AD group (0.63-0.93) and high/very high in the group without-AD (0.84-0.97). The measurements of knee extensors at 60°/s, knee extensors (peak torque and total work), with the exception of peak torque in the mild-AD group, and flexors (average peak torque) at 180°/s, and ankle dorsiflexors at 30°/s had the lowest of SEM% and MDC95% in the three groups. CONCLUSION: Concentric isokinetic measures are reliable for the assessment of knee and ankle muscle strength in community-dwelling older adults without and with AD in the mild and moderate stages.

Complexity of Knee Extensor Torque: Effect of Aging and Contraction Intensity.

ABSTRACT: Fiogbé, E, Vassimon-Barroso, V, Catai, AM, de Melo, RC, Quitério, RJ, Porta, A, and Takahashi, ACdM. Complexity of knee extensor torque: effect of aging and contraction intensity. J Strength Cond Res 35(4): 1050-1057, 2021-Assessing the knee extensors' torque complexity in older adults is relevant because these muscles are among the most involved in functional daily activities. This study aimed to investigate the effects of aging and isometric contraction intensity on knee extensor torque complexity. Eight young (24 ± 2.8 years) and 13 old adults (63 ± 2.8 years) performed 3 maximal (maximum voluntary contraction [MVC], duration = 10 seconds) and submaximal isometric contractions (SICs, targeted at 15, 30, and 40% of MVC, respectively) of knee extensors. Torque signals were sampled continuously, and the metrics of variability and complexity were calculated basing on the SIC torque data. The coefficient of variation (CV) was used to quantify the torque variability. The torque complexity was determined by calculating the corrected approximate entropy (CApEn) and sample entropy (SampEn) and its normalized versions (NCApEn and NSampEn). Young subjects produced greater isometric torque than older adults, and the CV was similar between both groups except at the highest force level (40% MVC) where young subjects' value was higher. The major novel finding of this investigation was that although the knee extensor torque complexity is reduced in older adults, its relationship with contraction intensity is similar to young subjects. This means that despite the age-related decrease of the interactions between the components of the neuromuscular system, the organization of force control remains preserved in older adults, at least up to just below the force midrange.

Effects of the Addition of a Dual Task to a Supervised Physical Exercise Program on Older Adults' Cognitive Performance.

The purpose of this study was to investigate the effects of the addition of a dual task to multicomponent training on cognition of active older adults. Eighty physically active older adults were divided into an intervention group (IG) and a control group (CG). Both groups performed multicomponent training over 12 weeks. The IG simultaneously performed exercises and cognitive tasks. The Mini-Mental State Examination, the Montreal Cognitive Assessment, and the Clock Drawing Test were used for cognitive assessments. The Timed Up and Go Test associated with a cognitive task was used for dual-task assessment. Significant interactions were not observed between groups in terms of the cognitive variables or the dual-task performance. An interaction was observed only for Timed Up and Go Test performance, which was better in the CG than in the IG. Active older adults showed no improvement in cognition following the addition of the dual task to the multicomponent training.

Maximal expiratory pressure and Valsalva manoeuvre do not produce similar cardiovascular responses in healthy men.

NEW FINDINGS: What is the central question of this study? This is the first study to evaluate and describe the cardiovascular responses during maximal expiratory pressure compared with the Valsalva manoeuvre, and whether those responses are similar. What is the main finding and its importance? This study showed that the duration of the manoeuvres appears to be responsible for the different physiological mechanisms involved in the cardiovascular responses to each manoeuvre and that the intensity of expiratory effort was related to the response in maximal expiratory pressure. These results are important to identify the risks to which subjects are exposed when performing these manoeuvres. The main purpose of this study was to compare the cardiovascular responses between the Valsalva manoeuvre (VM) and maximal expiratory pressure (MEP) and to evaluate the effect of age on these responses. Twenty-eight healthy men were evaluated and divided into two groups, younger (n = 15, 25 ± 5 years) and middle aged (n = 13, 50 ± 5 years), and they performed the VM and MEP measurement. The VM consisted of an expiratory effort (40 mmHg) against a manometer for 15 s, and the MEP was performed according to American Thoracic Society guidelines. The cardiovascular responses were analysed at rest, isotime (3 s), peak, nadir and recovery, and the cardiovascular variations (Δ) were calculated as peak or isotime minus resting values. For the statistical analysis, we used two-way ANOVA (P < 0.05). We observed that MEP and the VM generate similar changes in cardiac output (P > 0.05), but MEP presents higher values for mean arterial pressure (MAPPeak , MAPIsotime , ΔMAP and ΔMAPIsotime ) than those observed in the VM (P < 0.05). The execution time of the manoeuvres (VM ∼15 s and MEP ∼5 s) appears to be largely responsible for the activation of different physiological mechanisms involved in the cardiovascular control for each manoeuvre, and the intensity of expiratory effort is related to the higher response of MAP and peripheral vascular resistance (PVRIsotime and ΔPVRIsotime ) during MEP (P < 0.05). Moreover, it appears that age affects only the heart rate and PVR responses (P < 0.05), which were higher in the young and middle-aged group, respectively. Based on these findings, we can conclude that MEP and the VM do not generate similar cardiovascular responses, except for cardiac output.

Eccentric Torque-Producing Capacity is Influenced by Muscle Length in Older Healthy Adults.

Considering the importance of muscle strength to functional capacity in the elderly, the study investigated the effects of age on isokinetic performance and torque production as a function of muscle length. Eleven younger (24.2 ± 2.9 years) and 16 older men (62.7 ± 2.5 years) were subjected to concentric and eccentric isokinetic knee extension/flexion at 60 and 120° · s(-1) through a functional range of motion. The older group presented lower peak torque (in newton-meters) than the young group for both isokinetic contraction types (age effect, p < 0.001). Peak torque deficits in the older group were near 30 and 29% for concentric and eccentric contraction, respectively. Concentric peak torque was lower at 120° · s(-1) than at 60° · s(-1) for both groups (angular velocity effect, p < 0.001). Eccentric knee extension torque was the only exercise tested that showed an interaction effect between age and muscle length (p < 0.001), which suggested different torque responses to the muscle length between groups. Compared with the young group, the eccentric knee extension torque was 22-56% lower in the older group, with the deficits being lower in the shortened muscle length (22-27%) and higher (33-56%) in the stretched muscle length. In older men, the production of eccentric knee strength seems to be dependent on the muscle length. At more stretched positions, older subjects lose the capacity to generate eccentric knee extension torque. More studies are needed to assess the mechanisms involved in eccentric strength preservation with aging and its relationship with muscle length.

Effect of hormone replacement therapy on cardiac autonomic modulation.

OBJECTIVE: To investigate the effects of hormone replacement therapy (HRT) on heart rate variability (HRV) in healthy postmenopausal women. METHODS: Two groups were evaluated: group 1 (G1): 20 women not undergoing HRT (60 ± 5.89 years), group 2 (G2): 20 women undergoing HRT (59 ± 5.70 years). The HRTs involved were either conjugated equine estrogen with or without medroxyprogesterone, synthetic estrogen hormone, estradiol associated with norethisterone acetate or isoflavonoids. Electrocardiogram was recorded in the supine position for 10 min. Spectral analysis included low and high frequencies in absolute (LF and HF) and normalized units (LFnu and HFnu), which are predominantly cardiac sympathetic modulation (CSM) and cardiac vagal modulation (CVM) indicators, respectively. The LF/HF ratio was also calculated. Symbolic analysis involved the following indexes: 0V % (CSM indicator), 1V % (CSM and CVM indicators), 2LV % (predominantly CVM indicator) and 2UV % (CVM indicator). Shannon and conditional entropies were also calculated. RESULTS: Spectral analysis demonstrated that HRT affected HRV. LF, LFnu and LF/HF ratio were higher (showing increased CSM), while HFnu was lower (representing decreased CVM) in G2 than in G1. Correlations between complexity indices and HFnu were significant and positive only in G1. INTERPRETATION: Women undergoing HRT presented higher CSM and lower CVM than those who were not. Moreover, the expected positive relationship between CVM and complexity of HRV was found only in control group, thus indicating that CVM in women under therapy drop below a minimal value necessary to the association to become apparent, suggesting an unfavorable cardiac autonomic modulation in spite of HRT.

On the Validity of Single Regression Strategy for Granger Causality Assessment in Cardiovascular and Cardiorespiratory Control Studies.

Granger causality (GC) analysis is based on the comparison between prediction error variances computed over the full and restricted models after identifying the coefficients of appropriate vector regressions. GC markers can be computed via a double regression (DR) approach identifying two separate, independent models and a single regression (SR) strategy optimizing the description of the dynamics of the target over the full model and, then, reusing some parts of it in the restricted model. The present study compares the SR and DR strategies over heart period (HP), systolic arterial pressure (SAP) and respiration (R) beat-to-beat series collected during a graded orthostatic challenge induced by head-up tilt in 17 healthy individuals (age: 21-36 yrs; median: 29 yrs; 9 females and 8 males). We found that the DR approach was more powerful than the SR one in detecting the expected stronger involvement of the baroreflex during the challenge, while the expected weaker cardiorespiratory coupling was identified by both SR and DR strategies. The less powerful ability of the SR approach was the result of the greater variance of GC markers compared to the DR strategy. We conclude that, contrary to the suggestions present in literature, the SR approach is not necessarily associated with a smaller dispersion of GC markers. Moreover, we suggest that additional factors, such as the strategy utilized to build embedding spaces and metric utilized to compare prediction error variances, might play an important role in differentiating SR and DR approaches.

Life-space mobility in older adults with Alzheimer's-type dementia.

BACKGROUND: Mobility is an important component of functioning. Motor and cognitive impairment in older people with Alzheimer's disease can exert a negative impact on life-space mobility. OBJECTIVE: To compare life-space mobility in older adults with mild and moderate Alzheimer-type dementia and those without dementia and determine associations with health factors. METHODS: Life-space mobility was assessed using the Life Space Assessment (LSA) in 33 older adults with Alzheimer-type dementia (AD group) and 24 older adults without dementia (WD group). The World Health Organization Disability Assessment Schedule (WHODAS 2.0), Addenbrooke's Cognitive Examination (ACE-R), Geriatric Depression Scale (GDS), Modified Baecke Questionnaire for Older Adults (MBQOA), and Short Physical Performance Battery (SPPB) were completed. Statistical analysis was performed with unpaired t-test or Mann-Whitney tests for comparisons between groups and Spearman's correlation test. RESULTS: The AD group had a lower total LSA score compared to the WD group (44 vs 65, mean difference = -20.7 [95% CI: -28.6, -12.9]), 21% of the AD group were restricted to their homes when no assistance was available. In both groups, moderate correlations were found between LSA and both functioning and physical activity level. Symptoms of depression presented moderate correlation only in the WD group. CONCLUSIONS: Older adults with AD have lower life-space mobility and require assistance to achieve higher levels of mobility. CLINICAL IMPLICATIONS: LSA can help assess life-space mobility. Encouraging and enabling assistance is fundamental to a greater life-space for older adults with dementia.

The degree of engagement of cardiac and sympathetic arms of the baroreflex does not depend on the absolute value and sign of arterial pressure variations.

Objective.The percentages of cardiac and sympathetic baroreflex patterns detected via baroreflex sequence (SEQ) technique from spontaneous variability of heart period (HP) and systolic arterial pressure (SAP) and of muscle nerve sympathetic activity (MSNA) burst rate and diastolic arterial pressure (DAP) are utilized to assess the level of the baroreflex engagement. The cardiac baroreflex patterns can be distinguished in those featuring both HP and SAP increases (cSEQ++) and decreases (cSEQ--), while the sympathetic baroreflex patterns in those featuring a MSNA burst rate decrease and a DAP increase (sSEQ+-) and vice versa (sSEQ-+). The present study aims to assess the modifications of the involvement of the cardiac and sympathetic arms of the baroreflex with age and postural stimulus intensity.Approach.We monitored the percentages of cSEQ++ (%cSEQ++) and cSEQ-- (%cSEQ--) in 100 healthy subjects (age: 21-70 years, 54 males, 46 females), divided into five sex-balanced groups consisting of 20 subjects in each decade at rest in supine position and during active standing (STAND). We evaluated %cSEQ++, %cSEQ--, and the percentages of sSEQ+- (%sSEQ+-) and sSEQ-+ (%sSEQ-+) in 12 young healthy subjects (age 23 ± 2 years, 3 females, 9 males) undergoing incremental head-up tilt.Main results.We found that: (i) %cSEQ++ and %cSEQ-- decreased with age and increased with STAND and postural stimulus intensity; (ii) %sSEQ+- and %sSEQ-+ augmented with postural challenge magnitude; (iii) the level of cardiac and sympathetic baroreflex engagement did not depend on either the absolute value of arterial pressure or the direction of its changes.Significance.This study stresses the limited ability of the cardiac and sympathetic arms of the baroreflex in controlling absolute arterial pressure values and the equivalent ability of both positive and negative arterial pressure changes in soliciting them.

Linear and nonlinear analysis of heart rate variability in coronary disease.

OBJECTIVE: Coronary artery disease (CAD) and acute myocardial infarction (AMI) are associated with a reduction of heart rate variability (HRV). The aim of this study was to compare the HRV of CAD patients with and without AMI (CAD-AMI) with health-matched controls by linear (spectral analysis) and nonlinear [Shannon entropy (SE), conditional entropy (CE) and symbolic analysis (SA)] analysis. METHODS: Fifty-eight men were divided into three groups: healthy (n = 19, 57 ± 4 years), CAD (n = 20, 56 ± 10 years) and CAD-AMI (n = 19, 54 ± 12 years). The RR intervals were recorded at rest in the supine position for 10 min with an HR monitor (Polar(®)S810i). A series of 250 beats was selected to analyze variance, spectral analysis, SE, CE [complexity index (CI), normalized CI (NCI)] and SA (0V, 1V, 2LV and 2ULV patterns), as well as 0V (no significant variation) and 2ULV (two significant unlike variations), which reflect sympathetic and vagal modulation, respectively. One-way ANOVA (or the Kruskal-Wallis test when appropriate) and Pearson correlation were used. RESULTS: The CAD group had higher body mass index and weight than the CAD-AMI group, but no differences were found between the healthy and AMI groups. There were no differences between the groups regarding linear and nonlinear analysis. The 0V and 2ULV patterns were significantly correlated with the SE, CI and NCI of the three groups. INTERPRETATION: There was no difference between the groups regarding cardiac autonomic modulation by linear and nonlinear methods, which may be due to beta-blocker use, coronary angioplasty and the exercise capacity of healthy subjects.

Can timed up and go subtasks predict functional decline in older adults with cognitive impairment?

Even in the early stages of cognitive impairment, older people can present important motor alterations. However, there are no studies that have investigated Timed Up and Go (TUG) and its subtasks in predicting impairment of functional capacity over time in this population. Objectives: The aim of this study was to verify if the TUG test and its subtasks can predict functional decline over 32 months in older adults with mild cognitive impairment (MCI) and mild Alzheimer's disease (AD). Methods: This is a prospective 32-month follow-up study, including at baseline 78 older adults (MCI: n=40; AD: n=38). The TUG and its subtasks (e.g., sit-to-stand, walking forward, turn, walking back, and turn-to-sit) were performed at baseline using the Qualisys Motion system. Functional capacity was assessed at baseline and after 32 months. Results: After follow-up, the sample had 45 older adults (MCI: n=25; AD: n=20). Of these, 28 declined functional capacity (MCI: n=13; AD: n=15). No TUG variable significantly predicted (p>0.05) functional decline in both groups, by univariate logistic regression analysis with the covariate gender. Conclusions: Although older adults with MCI and mild AD declined functional capacity, the TUG test and its subtasks could not predict this decline over 32 months.

Mesmo nos estágios iniciais do comprometimento cognitivo, os idosos podem apresentar alterações motoras importantes. No entanto, não há estudos que tenham investigado o timed up and go (TUG) e suas subtarefas como preditores do comprometimento da capacidade funcional ao longo do tempo nessa população. Objetivos: O objetivo deste estudo foi verificar se o teste timed up and go (TUG) e suas subtarefas podem predizer o declínio funcional ao longo de 32 meses em idosos com comprometimento cognitivo leve (CCL) e doença de Alzheimer leve (DA). Métodos: Este é um estudo prospectivo de acompanhamento de 32 meses, que incluiu no início do estudo 78 idosos (CCL: n=40; DA: n=38). O TUG e suas subtarefas (sentar para levantar, caminhar para frente, virar, caminhar para trás e girar para sentar) foram realizados na linha de base pelo sistema Qualisys Motion. A capacidade funcional foi avaliada no início e após 32 meses. Resultados: Depois do seguimento, a amostra foi composta de 45 idosos (CCL: n=25; DA: n=20). Destes, 28 tiveram a capacidade funcional diminuída (CCL: n=13; DA: n=15). Nenhuma variável do TUG previu declínio funcional significativamente estatístico (p>0,05) em nenhum dos grupos, por meio da análise de regressão logística univariada com a covariável sexo. Conclusões: Embora os idosos com CCL e DA leve tenham tido sua capacidade funcional diminuída, o teste TUG e suas subtarefas não puderam prever esse declínio em 32 meses.

Reproducibility of Assessment Tests Addressing Body Structure and Function and Activity in Older Adults With Dementia: A Systematic Review.

OBJECTIVE: The purpose of this study was to analyze the relative and absolute reliability of assessment tests addressing body structure and function and activity in older adults with dementia. METHODS: Medline, Embase, Web of Science, The Cochrane Library, and Scielo were searched from inception until March 2021. Two independent reviewers performed the selection process based on titles, abstracts, and full text. Reliability studies of assessment tests in older adults with dementia were included. Methodological quality of the studies was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist. Relative reliability was analyzed using the intraclass correlation coefficient (ICC) interpreted based on Munro classification. Absolute reliability was analyzed using the minimal detectable change (MDC) and standard error of measurement. RESULTS: Fifteen studies involving a total of 560 older adults with dementia were included. Nineteen assessment tests were identified: 13 addressing body structure and function (muscle strength, postural balance, cardiorespiratory fitness) and 6 addressing activity (walking and mobility). Studies determined test-retest and interrater reliability. Fifteen studies evaluated relative reliability using the ICC, with values ranging from no or small correlation to very high correlations. Ten studies evaluated absolute reliability using the MDC or standard error of measurement or both. CONCLUSION: Relative reliability of the assessment tests for body structure and function and activity was high to very high based on ICCs, demonstrating good reproducibility. Regarding absolute reliability, the analysis of the MDC values revealed the need for substantial change to determine that a real change had occurred. Future investigations should consider the type of dementia and standardization of verbal encouragement during the assessment. IMPACT: This review identified the good reproducibility of assessment tests of body structure and function (muscle strength, postural balance, cardiorespiratory fitness) and activity (walking and mobility) domains in older adults with dementia. Clinically important values may differ when older adults with dementia of diverse etiologies are analyzed together and older adults specifically with Alzheimer disease. Identifying the type of dementia, analyzing types of dementia separately, and standardizing verbal commands during the execution of tests is of considerable clinical importance for this population of older adults.

Correlation between changes in Timed Up and Go performance and cognition in older people with mild cognitive impairment: A longitudinal study.

BACKGROUND: Compare changes in performance on subtasks of the Timed Up and Go test over 32 months in older adults with and without mild cognitive impairment; analyze the correlation between frontal cognitive functions at baseline and changes in Timed Up and Go subtasks over time. METHODS: A longitudinal study was conducted involving 31 older adults (15 with and 16 without cognitive impairment). Functional mobility was assessed at both evaluations using an adapted version of the Timed Up and Go test and the Qualisys motion system. The test was divided into five subtasks: sit-to-stand, walking forward, turn-to-walk, walking back and turn-to-sit. Cognition was assessed at baseline using the Frontal Assessment Battery and the Clock Drawing Test. FINDINGS: Significant differences in changes in the sit-to-stand subtask over time were found between groups. The difference in the time required to conclude this subtask was greater in the older adults with cognitive impairment. However, the difference in kinematic variables (peak trunk speed and range of motion) was greater in the group without cognitive impairment. Strong and moderate correlations were found between frontal cognitive functions and changes in Timed Up and Go subtasks, especially those involving transitions (sit-to-stand, turn-to-walk and turn-to-sit) in both groups. INTERPRETATION: Motor intervention protocols should incorporate the sit-to-stand subtask in older adults with mild cognitive impairment. Moreover, changes in more complex subtasks seem to be related to frontal cognitive performance at baseline. Therefore, treatments that combine motor and cognitive functions should be administered to older adults regardless of cognitive impairment.

Self-management strategies and multicomponent training to mitigate the effects of the interruption of physical exercise programmes in the pandemic context on functionality, sedentary behaviour, physical capacity, mental health, body composition and quality of life in older adults: a blinded randomized controlled study protocol.

BACKGROUND: Considering the confinement recommended by the World Health Organization due to the pandemic caused by COVID-19, many community physical exercise programmes for older adults have had their activities cancelled. In this context, proposing strategies to recover the possible adverse effects of the confinement period is pertinent. The use of self-management strategies associated with regular physical activity reduces sedentary behaviour and improves physical capacity in older adults. Thus, the purpose of this study was to describe a multicomponent training programme combined with a self-management strategy protocol to mitigate the effects of interruptions in physical exercise programmes on functionality, physical capacity, mental health, body composition and quality of life in older adults. METHODS: This will be a blinded, randomized and controlled clinical trial performed in São Carlos, SP, Brazil. Eighty older adults will be divided into two groups: multicomponent training (Multi) and multicomponent training + self-management strategies (Multi+SM). The intervention will be performed over 16 weeks on three alternate days of every week, with 50-min sessions. The assessment of physical capacity will be performed before the interruption of physical exercise programmes (T0: initial assessment, March 2020), preintervention (T1: immediately after the return of the exercise programme) and postintervention (T2). The assessments of physical activity level, quality of life, mental health, functionality and body composition will be performed at T1 and T2. DISCUSSION: The results from this MC+SM protocol will allow us to contribute clinical support to evaluate the variables analysed and to guide future public health policies with the aim of minimizing the possible deleterious effects arising from the physical exercise interruption periods caused by epidemics and pandemics. TRIAL REGISTRATION: RBR-10zs97gk . Prospectively registered in Brazilian Registry of Clinical Trials (ReBEC) on 17 June 2021. Registry name: Use of self-management strategies combined with multicomponent training to mitigate the effects of social distancing due to COVID-19 on capacity, physical capacity, mental health and quality of life in older adults - A blind, randomized and controlled clinical trial.

Causal relationships between heart period and systolic arterial pressure during graded head-up tilt.

In physiological conditions, heart period (HP) affects systolic arterial pressure (SAP) through diastolic runoff and Starling's law, but, the reverse relation also holds as a result of the continuous action of baroreflex control. The prevailing mechanism sets the dominant temporal direction in the HP-SAP interactions (i.e., causality). We exploited cross-conditional entropy to assess HP-SAP causality. A traditional approach based on phases was applied for comparison. The ability of the approach to detect the lack of causal link from SAP to HP was assessed on 8 short-term (STHT) and 11 long-term heart transplant (LTHT) recipients (i.e., less than and more than 2 yr after transplantation, respectively). In addition, spontaneous HP and SAP variabilities were extracted from 17 healthy humans (ages 21-36 yr, median age 29 yr; 9 females) at rest and during graded head-up tilt. The tilt table inclinations ranged from 15 to 75° and were changed in steps of 15°. All subjects underwent recordings at every step in random order. The approach detected the lack of causal relation from SAP to HP in STHT recipients and the gradual restoration of the causal link from SAP to HP with time after transplantation in the LTHT recipients. The head-up tilt protocol induced the progressive shift from the prevalent causal direction from HP to SAP to the reverse causality (i.e., from SAP to HP) with tilt table inclination in healthy subjects. Transformation of phases into time shifts and comparison with baroreflex latency supported this conclusion. The proposed approach is highly efficient because it does not require the knowledge of baroreflex latency. The dependence of causality on tilt table inclination suggests that "spontaneous" baroreflex sensitivity estimated using noncausal methods (e.g., spectral and cross-spectral approaches) is more reliable at the highest tilt table inclinations.

Influence of third-generation oral contraceptives on the complexity analysis and symbolic dynamics of heart rate variability.

OBJECTIVE: To evaluate the influence of oral contraceptives (OCs) containing 20 µg ethinylestradiol (EE) and 150 µg gestodene (GEST) on the autonomic modulation of heart rate (HR) in women. METHODS: One-hundred and fifty-five women aged 24 ± 2 years were divided into four groups according to their physical activity and the use or not of an OC: active-OC, active-non-OC (NOC), sedentary-OC, and sedentary-NOC. The heart rate was registered in real time based on the electrocardiogram signal for 15 minutes, in the supine-position. The heart rate variability (HRV) was analysed using Shannon's entropy (SE), conditional entropy (complexity index [CInd] and normalised CInd [NCI]), and symbolic analysis (0V%, 1V%, 2LV%, and 2ULV%). For statistical analysis the Kruskal-Wallis test with Dunn post hoc and the Wilcoxon test (p < 0.05 was considered significant) were applied. RESULTS: Treatment with this COC caused no significant changes in SE, CInd, NCI, or symbolic analysis in either active or sedentary groups. Active groups presented higher values for SE and 2ULV%, and lower values for 0V% when compared to sedentary groups (p < 0.05). CONCLUSION: HRV patterns differed depending on life style; the non-linear method applied was highly reliable for identifying these changes. The use of OCs containing 20 µg EE and 150 µg GEST does not influence HR autonomic modulation.

Effects of physical exercise on the cognition of older adults with frailty syndrome: A systematic review and meta-analysis of randomized trials.

OBJECTIVES: To analyze the effects of physical exercise on the cognition of community-dwelling older adults with frailty syndrome, through randomized clinical trials. DATA SOURCES: Articles published until March 2020 were searched in the databases Science Direct, Scopus, Web of Science, PubMed, Lilacs, Cochrane, IEEE, EMBASE, and SciELO. Search terms included frailty, aged, exercise, rehabilitation, and cognition. For the Portuguese language, equivalent terms were used. STUDY SELECTION: Only randomized clinical trials that used physical exercise as an intervention method in community-dwelling older adults (≥ 60y.) with frailty syndrome, and which performed cognitive assessments before and after the intervention were included. DATA EXTRACTION: Two authors performed data extraction using predefined data fields. The risk of bias of the six included studies was assessed using the PEDro scale. DATA SYNTHESIS: In total, 4501 studies were found. After the selection process, 6 studies were included in the systematic review and 4 studies in the meta-analysis, all with a low risk of bias. The studies included 655 community-dwelling older adults with frailty syndrome. The types of intervention varied, with multicomponent physical exercise being the most frequent. The cognitive assessments were diverse, and the Mini-mental State Examination, Trail Making Test forms A and B, and Digit Span test were the most frequently applied. A meta-analysis was performed with Global Cognition and Trail Making Test forms A and B. The data from the meta-analysis showed that physical exercise improves Global Cognition (Mean Difference = 2.26; 95% CI, 0.42 - 4.09; P = 0.02) and mental flexibility (Trail Making Test B) (Mean Difference = -30.45; 95% CI; - 47.72 - -13.19; P = 0.0005). CONCLUSION: Interventions with physical exercise promote benefits in global cognition and mental flexibility of older adults with frailty syndrome.

Cardiac Autonomic Modulation Response Before, During, and After Submaximal Exercise in Older Adults With Intellectual Disability.

The analysis of the heart rate variability (HRV) consists of changes in the time intervals between consecutive R waves. It provides information on the autonomic nervous system regulation and it is a predictor of adverse cardiovascular events. Several studies analyzed this parameter in youth and adults with Intellectual Disability (ID). Nevertheless, there is a lack of information regarding the HRV before, during, and after exercise in older adults with ID. Therefore, we aimed to describe and compare the cardiac autonomic modulation before, during, and after the six-minute walk test (6MWT) in older adults with and without ID. Twenty-four volunteers with ID and 24 without ID (non-ID) participated in this study. HRV was assessed by R-R intervals at rest, during and after the 6MWT. At rest and recovery periods, the participants remained sited. The symbolic analysis was used to evaluate non-linear HRV components. The recovery HR kinetics was assessed by the mean response time, which is equivalent to time constant (τ)+time delay (TD). Between groups differences in HRV variables were not significant. During the recovery period, HR kinetics time variables showed significant better results in non-ID participants (TD: 6±5s vs. 15±11s; τ: 19±10s vs. 35±17s; and MRT: 25±9s vs. 50±11s, all p<0.050). In conclusion, our results suggest that the HRV in older adults with and without ID is similar during rest, exercise, and recovery. Recovery HR kinetics after the 6MWT was slower in older adults with ID. The reason for these results may be a reduced post-exercise vagal rebound in older adults with ID.