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1.
BMC Public Health ; 24(1): 1582, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38872140

RESUMO

Older adults who are frail are one of the most sedentary and the least physically active age groups. Prolonged sedentary time is associated with increased risk of negative health outcomes. To help design effective and sustainable content and optimize the uptake of sedentary behaviour interventions, an in-depth understanding of older adults' perceptions of sedentary behaviour is needed; however, most qualitative studies have been conducted in healthy older adults. The aim of this study was to explore perspectives of sedentary behaviour within the context of older adults who are pre-frail and frail after the winter and spring. We included participants if they: (1) spoke English or attended with a translator or caregiver, (2) were ≥ 60 years, and (3) were frail on the Morley Frail Scale. We utilized a qualitative description methodology including a semi-structured in-depth interview and thematic content analysis. Concepts from the COM-B (Capability Opportunity Motivation-Behaviour) model were used to guide the semi-structured interviews and analysis. To ensure credibility of the data, we used an audit trail and analyst triangulation. We recruited 21 older adults (72 ± 7.3 years, 13 females, 13 frail) from southwestern Ontario, Canada. Two individuals were lost to follow-up due to medical mistrust and worse health. We transcribed 39 audio recordings. We identified three salient themes: (1) older adults rationalize their sedentary behaviours through cognitive dissonance (reflective motivation), (2) urban cities in southwestern Ontario may not be "age-friendly" (physical opportunity), and (3) exercise is something people "have to do", but hobbies are for enjoyment despite medical conditions (psychological capability). Perspectives of sedentary behaviour were different in the winter versus spring, with participants perceiving themselves to be less active in winter. Incorporating dissonance-based interventions as part of an educational program could be used to target the reflective motivation and psychological capability components. Future research should consider interdisciplinary collaborations with environmental gerontology to develop age-friendly communities that promote meaningful mobility to target physical opportunity.


Assuntos
Idoso Fragilizado , Pesquisa Qualitativa , Comportamento Sedentário , Humanos , Feminino , Idoso , Masculino , Idoso Fragilizado/psicologia , Pessoa de Meia-Idade , Ontário , Idoso de 80 Anos ou mais , Entrevistas como Assunto , Exercício Físico/psicologia
2.
BMC Public Health ; 24(1): 1239, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711051

RESUMO

The adoption and maintenance of physical activity (PA) is an important health behavior. This paper presents the first comprehensive empirical test of the Physical Activity Adoption and Maintenance (PAAM) model, which proposes that a combination of explicit (e.g., intention) and implicit (e.g., habit,, affect) self-regulatory processes is involved in PA adoption and maintenance. Data were collected via online questionnaires in English, German, and Italian at two measurement points four weeks apart. The study included 422 participants (Mage= 25.3, SDage= 10.1; 74.2% women) from Germany, Switzerland, Italy, Canada, and the U.S. The study results largely supported the assumptions of the PAAM model, indicating that intentions and habits significantly mediate the effects of past PA on future PA. In addition, the effect of past PA on future PA was shown to be significant through a mediation chain involving affect and habit. Although the hypothesis that trait self-regulation moderates the intention-behavior relationship was not supported, a significant moderating effect of affect on the same relationship was observed. The results suggest that interventions targeting both explicit and implicit processes may be effective in promoting PA adoption and maintenance.


Assuntos
Exercício Físico , Comportamentos Relacionados com a Saúde , Intenção , Humanos , Feminino , Masculino , Exercício Físico/psicologia , Adulto , Inquéritos e Questionários , Adulto Jovem , Pessoa de Meia-Idade , Modelos Psicológicos , Adolescente
3.
J Sport Exerc Psychol ; 44(6): 409-419, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270628

RESUMO

Physical activity (PA) guidelines are informed by epidemiological evidence but do not account for people's motivation for exerting physical effort. Previous research has shown that people are less motivated to engage in moderate- to vigorous-intensity PA when fatigued. In a two-study series, we investigated how intensity and duration affected people's willingness to engage in PA using an effort-discounting paradigm. A secondary purpose was to examine whether effort discounting was affected by mental fatigue. Both studies revealed a significant Intensity × Duration interaction demonstrating a reduced willingness to engage in PA of higher intensities across increasing duration levels. Study 1 demonstrated greater effort discounting for vigorous-intensity PA with increasing mental fatigue; however, this effect was not observed in Study 2. Findings provide novel insight toward people's motivation for engaging in PA based on the properties of the task, and some evidence suggesting feelings of fatigue may also influence motivation to exert physical effort.


Assuntos
Tomada de Decisões , Esforço Físico , Humanos , Motivação , Fadiga Mental , Exercício Físico , Recompensa
4.
Age Ageing ; 50(4): 1084-1092, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-33338209

RESUMO

BACKGROUND: dance is a mind-body activity that stimulates neuroplasticity. We explored the effect of dance on cognitive function in older adults. METHODS: we searched MEDLINE, EMBASE, CENTRAL and PsycInfo databases from inception to August 2020 (PROSPERO:CRD42017057138). Inclusion criteria were (i) randomised controlled trials (ii) older adults (aged ≥ 55 years), (iii) intervention-dance and (iv) outcome-cognitive function. Cognitive domains were classified with the Diagnostic and Statistical Manual of Mental Disorders-5 Neurocognitive Framework. Meta-analyses were performed in RevMan5.3 and certainty of evidence with GradePro. RESULTS: we reviewed 3,997 records and included 11 studies (N = 1,412 participants). Seven studies included only healthy older adults and four included those with mild cognitive impairment (MCI). Dance interventions varied in frequency (1-3×/week), time (35-60 minutes), duration (3-12 months) and type. We found a mean difference (MD) = 1.58 (95% confidence interval [CI) = 0.21-2.95) on the Mini Mental State Examination for global cognitive function (moderate-certainty evidence), and the Wechsler Memory Test for learning and memory had an MD = 3.02 (95% CI = 1.38-4.65; low-certainty evidence). On the Trail Making Test-A for complex attention, MD = 3.07 (95% CI = -0.81 to 6.95; high-certainty evidence) and on the Trail Making Test-B for executive function, MD = -4.12 (95% CI = -21.28 to 13.03; moderate-certainty evidence). Subgroup analyses did not suggest consistently greater effects in older adults with MCI. Evidence is uncertain for language, and no studies evaluated social cognition or perceptual-motor function. CONCLUSIONS: dance probably improves global cognitive function and executive function. However, there is little difference in complex attention, and evidence also suggests little effect on learning and memory. Future research is needed to determine the optimal dose and if dance results in greater cognitive benefits than other types of physical activity and exercise.


Assuntos
Cognição , Disfunção Cognitiva , Idoso , Função Executiva , Humanos
5.
BMC Public Health ; 20(1): 426, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32234011

RESUMO

BACKGROUND: The overarching objective of the study is to obtain a comprehensive understanding of the salient factors predicting changes in physical activity (PA) during adolescents' transition into emerging adulthood. Using the Multi-Process Action Control model as our guiding framework, we will examine how implicit and explicit psychological processes along with regulatory practices impact PA change during this major life transition. Additionally, we will use a real-time data capture method called Ecological Momentary Assessment to further investigate how environmental and contextual factors, and momentary psychosocial influences effect PA patterns across this dynamic life stage. METHODS: The ADAPT study is a 4-year project comprised of two interrelated studies. Study I is a large prospective cohort study that will invite all grade 11 students across one large school board (a total of seven secondary schools) to participate by completing an online questionnaire. Using a cluster randomization approach, a subset of students from each school will be invited to participate in Study II, whereby participants will wear an accelerometer and complete Ecological Momentary Assessments 5 times a day over a 7-day study period. For both studies, following baseline assessments, there will be three annual follow-up assessments approximately 12 months apart. DISCUSSION: The current study represents one of the largest longitudinal cohort studies examining PA and its determinants and associated consequences among adolescents transitioning out of high school into emerging adulthood. Findings from this study will provide a much more in-depth understanding of how and why changes in PA behaviour occur across this first major life transition.


Assuntos
Comportamento do Adolescente , Exercício Físico/psicologia , Acontecimentos que Mudam a Vida , Instituições Acadêmicas , Estudantes/psicologia , Adolescente , Adulto , Estudos de Coortes , Meio Ambiente , Feminino , Humanos , Estudos Longitudinais , Masculino , Atividade Motora , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Meio Social , Inquéritos e Questionários
6.
J Sport Exerc Psychol ; 42(4): 314-322, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711396

RESUMO

Social interactions are theorized to inform relation-inferred self-efficacy (RISE), which, in turn, may influence self-efficacy and behavior. This study investigated the effects of peer encouragement on RISE, task self-efficacy, and physical performance. Children (N = 84) were assigned to dyads and randomized to provide peer encouragement to one another or not (control group). Participants completed two endurance handgrip trials, separated by a cognitively demanding task intended to induce mental fatigue and increase the salience of the peer encouragement manipulation. Participants in the experimental group exchanged words of encouragement prior to the second endurance trial, whereas those in the control group did not. The peer encouragement group reported higher RISE and showed increased performance across trials compared with controls. Providing peer encouragement prior to a challenging physical task was associated with more positive RISE perceptions and improved physical performance.

7.
Ann Behav Med ; 53(5): 405-414, 2019 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29985969

RESUMO

BACKGROUND: Exerting cognitive control results in mental fatigue, which is associated with impaired performance during physical endurance tasks. However, there has been little research on the effects of mental fatigue on people's perceptions or behaviors involving lifestyle or recreational exercise. PURPOSE: The purpose of this study was to examine the effect of mental fatigue on intended physical exertion and exercise performance reflective of current physical activity guidelines. METHODS: Using a counterbalanced design, participants completed two 50-min experimental manipulations (high vs. low cognitive control exertion) before exercising at a self-selected intensity for 30 min. At visit 1, participants performed a graded exercise task to gain familiarity with a range of exercise intensities and rating of perceived exertion (RPE) while exercising. At visits 2 and 3, participants rated their intended RPE for the exercise session, performed the experimental manipulations, re-rated their intended RPE, and then completed 30-min of exercise on a cycle ergometer. Total work performed while exercising was recorded for each session. RESULTS: Compared with the low cognitive control condition, the high cognitive control manipulation resulted in significantly greater mental fatigue (d = .73), significantly greater reductions in intended RPE (mean difference = -0.62), and significantly less total work (-12.7 kJ) performed during the exercise session. CONCLUSIONS: Mental fatigue alters the amount of physical effort people are willing to invest in an exercise workout and follow through with those intentions by doing less work. These are the first results showing people may deliberately adjust their physical effort to cope with mental fatigue.


Assuntos
Função Executiva/fisiologia , Exercício Físico/fisiologia , Comportamentos Relacionados com a Saúde/fisiologia , Intenção , Fadiga Mental/fisiopatologia , Esforço Físico/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
8.
Epilepsy Behav ; 94: 158-166, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30939411

RESUMO

PURPOSE: This study examined whether increasing physical activity (PA) through 6 months of behavioral counseling positively influenced depressive symptoms and quality of life (QoL) over 12 months among children with epilepsy (CWE). METHODS: A longitudinal multisite randomized controlled trial (RCT) was conducted with 8-14-year-old children with active epilepsy. Participants wore a pedometer to track daily PA and completed 3 measures at 4 time points to examine depressive symptoms and QoL. Stratified by site and activity level, participants were randomized to an intervention or control group. The 6-month intervention included 11 behavioral counseling sessions targeting self-regulation of PA. To assess the associations among PA, depression scores, and QoL, primary analysis involved mixed-effects models. RESULTS: We recruited 122 CWE, of whom 115 were randomized (Mage = 11 ±â€¯2; 50% female) and included in the analysis. The intervention did not increase PA in the treatment compared with the control group. No differences were found between groups over time during the subsequent 6 months, where PA decreased among all participants. Results did not show differences between the groups and over time for measures of depressive symptoms and QoL. SIGNIFICANCE: The intervention did not improve or sustain PA levels over 12 months. Both groups demonstrated declines in PA over one year, but there were no changes in depression scores or QoL. As most participants were already nearly reaching the Canadian average of step counts of children their age, with a baseline daily step count of over 9000, there may be a challenge for further increasing PA over a longer period.


Assuntos
Depressão/psicologia , Depressão/terapia , Epilepsia/psicologia , Epilepsia/terapia , Exercício Físico , Qualidade de Vida , Adolescente , Criança , Aconselhamento , Depressão/etiologia , Epilepsia/complicações , Terapia por Exercício/métodos , Feminino , Humanos , Estudos Longitudinais , Masculino , Resultados Negativos , Autocuidado
9.
J Sports Sci ; 35(18): 1-9, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27681889

RESUMO

We investigated effects of a brief (10.5 min) cognitively demanding task on graded exercise test performance. Untrained, university students (N = 15) completed two graded exercise tests in counterbalanced, randomised order. One test was preceded by restful viewing of a documentary video (control); the other by a stop-signal task. Cardiorespiratory functions and perceived exertion were monitored during exercise. Peak power output (W) was lower following the stop-signal task (M = 240.03, SD = 53.37) compared to control (M = 246.03, SD = 52.60), P = 0.002, ηP2 = 0.493, as was [Formula: see text] (P = 0.042, Cohen's d = 0.55). Perceived exertion was significantly higher at 50% (d = 0.77) and 75% (d = 0.83) of iso-time following the cognitive task (Ps ≤ 0.01). Results are consistent with research showing negative carryover effects of cognitively demanding tasks on whole-body endurance performance. Results also support the psychobiological model of exercise as performance of the cognitive task did not affect perceived exertion when exercise task demands were lower, but lead to greater perceived exertion and earlier withdrawal of effort at higher levels of exercise task demand. Findings have implications for understanding psychological determinants of exercise performance and conditions that may lead to underestimation of [Formula: see text].


Assuntos
Cognição , Exercício Físico/psicologia , Percepção/fisiologia , Esforço Físico , Autocontrole/psicologia , Teste de Esforço/métodos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Fadiga Mental/fisiopatologia , Consumo de Oxigênio/fisiologia , Troca Gasosa Pulmonar , Taxa Respiratória/fisiologia , Volume de Ventilação Pulmonar , Adulto Jovem
10.
J Sport Exerc Psychol ; 39(6): 385-396, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29424609

RESUMO

Physical performance is impaired following cognitive control exertion. Incentives can ameliorate adverse carryover effects of cognitive control exertion but have not been investigated for physical endurance. This study examined the effect of monetary incentives on physical performance and muscle activation following exposure to a mentally fatiguing, cognitive control task. Participants (N = 82) performed two isometric endurance handgrip trials separated by a 12-min cognitive control manipulation using a 2 (high cognitive control [HCC]/low cognitive control [LCC]) × 2 (incentive/no incentive) design. Mental fatigue was significantly higher in the HCC conditions. Performance decreased in the HCC/no incentive condition but was unaffected in the HCC/incentive condition, which did not differ from the low cognitive control conditions. Electromyography data revealed increased muscle activation in the HCC/no incentive condition, which was also attenuated in the HCC/incentive condition. Findings show that incentives counteract the negative effects of HCC on physical endurance and alter central drive to motor units.


Assuntos
Fadiga Mental/fisiopatologia , Motivação , Músculo Esquelético/fisiologia , Resistência Física , Eletromiografia , Feminino , Força da Mão , Humanos , Masculino , Adulto Jovem
11.
J Sports Sci ; 34(16): 1491-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26634389

RESUMO

This study examined the effect of autonomous motivational priming on motivation, attitudes and intentions towards high-intensity interval training (HIT). Participants (N = 42) performed a graded exercise test to determine their peak aerobic power (WPEAK). At a subsequent testing session, participants were randomised to complete either an autonomous or neutral motivational priming task followed by a 10 × 1 HIT exercise protocol, alternating 1-min bouts of hard (70% WPEAK) and light (12.5% WPEAK) exercises for 20 min. Participants primed with autonomous motivation reported greater enjoyment, P = .009, ηp(2) = .16, and perceived competence, P = .005, ηp(2) = .18, post-exercise compared to those in the neutral priming condition. Participants in the autonomous motivational priming condition also reported more positive attitudes, P = .014, ηp(2) = .14, towards HIT; however, there was no difference between the conditions for task motivation during HIT or intentions, P = .53, ηp(2) = .01, to engage in HIT. These findings highlight autonomous motivational priming as a method of enhancing affective and motivational experiences regarding HIT.


Assuntos
Afeto , Treinamento Intervalado de Alta Intensidade/psicologia , Motivação , Atitude , Feminino , Frequência Cardíaca , Humanos , Intenção , Masculino , Percepção/fisiologia , Esforço Físico , Prazer , Adulto Jovem
12.
J Sports Sci ; 33(5): 534-43, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25278342

RESUMO

The purpose of the study was to investigate the effects of two weeks of self-control strength training on maximum cardiovascular exercise performance. Forty-one participants completed a cognitive self-control depletion task (Stroop task) followed by a maximal graded cycling test and were randomized to training (maximal endurance contractions of spring handgrip trainers, twice daily) or no-treatment control groups. At follow-up (2 weeks), half of each group completed either a time-matched or trial-matched Stroop task followed by another maximal graded cycling test. Results showed a significant 2-way (training X time) interaction (P < 0.001), and a trend for the 3-way (training X time X cognitive task) interaction (P = 0.07). Decomposition of the interactions revealed that across sessions cycling performance increased in both training groups, did not change in the trial-matched cognitive task control group, and declined in the time-matched control group. We conclude that isometric handgrip training leads to self-control strength adaptations that enhance maximal cardiovascular exercise performance or tolerance of exercise at maximal levels of effort.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Exercício Físico/fisiologia , Exercício Físico/psicologia , Treinamento Resistido/métodos , Autocontrole , Adolescente , Teste de Esforço , Feminino , Força da Mão/fisiologia , Humanos , Contração Isométrica , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Teste de Stroop
13.
J Sports Sci ; 33(5): 487-97, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25260112

RESUMO

The purpose of this study was to explore the dose-response relationship between exercise and cognitive performance using an acute bout of isometric exercise. University students (N = 55) were randomly assigned to control, 30%, 50% and 70% of maximum voluntary handgrip contraction groups. Participants performed a modified Stroop task before and after completion of an isometric handgrip endurance trial at their assigned exercise intensity. Ratings of perceived exertion (RPE) and forearm muscle activation (EMG) showed linear trends of progressively greater RPE and muscle activation at greater exercise intensity levels. Regression analysis showed significant (P < .05) linear degradations in frequency of errors on the Stroop task with increasing exercise intensity. We conclude that performing isometric exercise until exhaustion is associated with reduced cognitive performance and that higher intensity isometric exercise leads to greater performance impairments in a linear dose-response manner.


Assuntos
Cognição , Exercício Físico/psicologia , Afeto , Eletromiografia , Exercício Físico/fisiologia , Feminino , Antebraço/fisiologia , Força da Mão/fisiologia , Humanos , Masculino , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Percepção/fisiologia , Esforço Físico/fisiologia , Teste de Stroop
14.
J Sport Exerc Psychol ; 37(5): 477-88, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26524094

RESUMO

The purpose of this study was to investigate the role of task self-efficacy as a psychological factor involved in the relationship between self-control depletion and physical endurance. Participants (N = 37) completed two isometric handgrip endurance trials, separated by a Stroop task, which was either congruent (control) or incongruent (causing depletion). Task self-efficacy for the second endurance trial was measured following the Stroop task. Participants in the depletion condition reported lower task self-efficacy and showed a greater reduction in performance on the second endurance trial when compared with controls. Task self-efficacy also mediated the relationship between self-control depletion and endurance performance. The results of this study provide evidence that task self-efficacy is negatively affected following self-control depletion. We recommend that task self-efficacy be further investigated as a psychological factor accounting for the negative change in self-control performance of physical endurance and sport tasks following self-control strength depletion.


Assuntos
Resistência Física/fisiologia , Desempenho Psicomotor/fisiologia , Autoeficácia , Autocontrole , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
15.
J Sport Exerc Psychol ; 36(2): 146-56, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24686951

RESUMO

Interpersonal feedback from coaches may be instrumental in the formation of children's self-efficacy to learn or perform sport skills. We report on two studies that explored perceived sources of self-efficacy and relation-inferred self-efficacy (RISE) in one-on-one interviews with sport camp participants (N = 61; ages 7-12) and focus groups with recreational league participants (N = 28; ages 8-12). Participants' responses indicated that prior experiences and socially constructed interactions contributed to the development of self-efficacy and RISE beliefs. Results support Bandura's (1997) theorizing that self-efficacy is developed through processing of experiential feedback as well as Lent and Lopez's (2002) tripartite theory proposing interpersonal feedback from influential others contributes to children's RISE and self-efficacy.


Assuntos
Desempenho Atlético/psicologia , Retroalimentação , Relações Interpessoais , Autoeficácia , Esportes , Adolescente , Acampamento , Criança , Feminino , Humanos , Entrevistas como Assunto , Masculino , Teoria Psicológica , Pesquisa Qualitativa
16.
PLoS One ; 19(5): e0290197, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753692

RESUMO

Older adults who are frail are likely to be sedentary. Prior interventions to reduce sedentary time in older adults have not been effective as there is little research about the context of sedentary behaviour (posture, location, purpose, social environment). Moreover, there is limited evidence on feasible measures to assess context of sedentary behaviour in older adults. The aim of our study was to determine the feasibility of measuring context of sedentary behaviour in older adults with pre-frailty or frailty using a combination of objective and self-report measures. We defined "feasibility process" using recruitment (20 participants within two-months), retention (85%), and refusal (20%) rates and "feasibility resource" if the measures capture context and can be linked (e.g., sitting-kitchen-eating-alone) and are all participants willing to use the measures. Context was assessed using a wearable sensor to assess posture, a smart home monitoring system for location, and an electronic or hard-copy diary for purpose and social context over three days in winter and spring. We approached 80 potential individuals, and 58 expressed interest; of the 58 individuals, 37 did not enroll due to lack of interest or medical mistrust (64% refusal). We recruited 21 older adults (72±7.3 years, 13 females, 13 frail) within two months and experienced two dropouts due to medical mistrust or worsening health (90% retention). The wearable sensor, indoor positioning system, and electronic diary accurately captured one domain of context, but the hard copy was often not completed with enough detail, so it was challenging to link it to the other devices. Although not all participants were willing to use the wearable sensor, indoor positioning system, or electronic diary, we were able to triage the measures of those who did. The use of wearable sensors and electronic diaries may be a feasible method to assess context of sedentary behaviour, but more research is needed with device-based measures in diverse groups.


Assuntos
Estudos de Viabilidade , Estações do Ano , Comportamento Sedentário , Dispositivos Eletrônicos Vestíveis , Humanos , Idoso , Feminino , Masculino , Estudos Longitudinais , Idoso Fragilizado , Idoso de 80 Anos ou mais , Autorrelato , Sistemas de Informação Geográfica
17.
Proc Natl Acad Sci U S A ; 107(37): 16222-7, 2010 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-20798349

RESUMO

The Ashkenazi Jewish (AJ) population has long been viewed as a genetic isolate, yet it is still unclear how population bottlenecks, admixture, or positive selection contribute to its genetic structure. Here we analyzed a large AJ cohort and found higher linkage disequilibrium (LD) and identity-by-descent relative to Europeans, as expected for an isolate. However, paradoxically we also found higher genetic diversity, a sign of an older or more admixed population but not of a long-term isolate. Recent reports have reaffirmed that the AJ population has a common Middle Eastern origin with other Jewish Diaspora populations, but also suggest that the AJ population, compared with other Jews, has had the most European admixture. Our analysis indeed revealed higher European admixture than predicted from previous Y-chromosome analyses. Moreover, we also show that admixture directly correlates with high LD, suggesting that admixture has increased both genetic diversity and LD in the AJ population. Additionally, we applied extended haplotype tests to determine whether positive selection can account for the level of AJ-prevalent diseases. We identified genomic regions under selection that account for lactose and alcohol tolerance, and although we found evidence for positive selection at some AJ-prevalent disease loci, the higher incidence of the majority of these diseases is likely the result of genetic drift following a bottleneck. Thus, the AJ population shows evidence of past founding events; however, admixture and selection have also strongly influenced its current genetic makeup.


Assuntos
Genética Populacional , Judeus/genética , Seleção Genética , Cromossomos Humanos , Variação Genética , Humanos , Desequilíbrio de Ligação
18.
J Sport Exerc Psychol ; 35(3): 239-49, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23798587

RESUMO

The purpose of this study was to examine the effects of depleted self-control strength on skill-based sports task performance. Sixty-two participants completed the following: a baseline dart-tossing task (20 tosses), with measures of accuracy, reaction time, and myoelectrical activity of the arms taken throughout; a self-control depletion (experimental) or a nondepletion (control) manipulation; and a second round of dart tossing. As hypothesized, participants in the experimental condition had poorer mean accuracy at Round 2 than control condition participants, and a significant decline in accuracy from Round 1 to Round 2. Experimental condition participants also demonstrated poorer consistency in accuracy compared with control condition participants at Round 2 and a significant deterioration in consistency from Round 1 to Round 2. In addition, consistency in reaction time improved significantly for the control group but not for the experimental group. The results of this study provide evidence that ego depletion effects occur in the performance of a skill-based sports task.


Assuntos
Desempenho Atlético/psicologia , Ego , Controle Interno-Externo , Análise e Desempenho de Tarefas , Adulto , Análise de Variância , Desempenho Atlético/fisiologia , Desempenho Atlético/estatística & dados numéricos , Atenção/fisiologia , Eletromiografia/métodos , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Teste de Stroop/estatística & dados numéricos , Adulto Jovem
19.
Psychol Sport Exerc ; 69: 102499, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37665934

RESUMO

BACKGROUND: Current research investigating the relationship between mental fatigue and physical activity behaviors relies on laboratory-based, experimental studies which lack ecological validity. OBJECTIVE: This study used ecological momentary assessment (EMA) to assess feelings of mental fatigue and subjective evaluations (benefits and costs) as predictors of moderate-to-vigorous intensity physical activity in the everyday lives of young adults. METHODS: One hundred participants (n = 22 males, n = 78 females, Mage = 20.60 years, 70% meeting or exceeding physical activity guidelines) responded to digital survey prompts up to four times a day and wore an accelerometer for seven consecutive days. Moderate-to-vigorous intensity physical activity in the 180-min time window following each survey prompt was recorded. Data from the 28 survey-moderate-to-vigorous intensity physical activity epochs were analyzed using multilevel mixed-effects linear modelling. RESULTS: Higher levels of mental fatigue than one's average level were associated with engaging in fewer moderate-to-vigorous intensity physical activity minutes (p = .004) and lower benefit vs. cost scores (p = .001). Higher benefit vs. cost scores than one's average level were associated with engaging in more minutes of moderate-to-vigorous intensity physical activity (p < .001). CONCLUSIONS: Results are the first to demonstrate outside the lab, that mental fatigue experienced in everyday life may amplify the perceived costs of moderate-to-vigorous intensity physical activity, with both factors playing a potential role in moderate-to-vigorous intensity physical activity decision-making. Future research may apply insights gained from this study in design and testing of real-time interventions promoting moderate-to-vigorous intensity physical activity.


Assuntos
Exercício Físico , Fadiga Mental , Feminino , Masculino , Adulto Jovem , Humanos , Adulto , Análise Custo-Benefício , Fadiga Mental/diagnóstico , Avaliação Momentânea Ecológica , Emoções
20.
Med Sci Sports Exerc ; 55(7): 1232-1240, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36878190

RESUMO

INTRODUCTION/PURPOSE: To determine personal, environmental, and participation factors that predict children's physical activity (PA) trajectories from preschool through to school years. METHODS: Two hundred seventy-nine children (4.5 ± 0.9 yr, 52% boys) were included in this study. Physical activity was collected via accelerometry at six different timepoints over 6.3 ± 0.6 yr. Time-stable variables were collected at baseline and included child's sex and ethnicity. Time-dependent variables were collected at six timepoints (age, years) and included household income (CAD), parental total PA, parental influence on PA, and parent-reported child's quality of life, child's sleep, and child's amount of weekend outdoor PA. Group-based trajectory modeling was applied to identify trajectories of moderate-to-vigorous PA (MVPA) and total PA (TPA). Multivariable regression analysis identified personal, environmental, and participation factors associated with trajectory membership. RESULTS: Three trajectories were identified for each of MVPA and TPA. Group 3 in MVPA and TPA expressed the most PA over time, with increased activity from timepoints 1 to 3, and then declining from timepoints 4 to 6. For the group 3 MVPA trajectory, male sex (ß estimate, 3.437; P = 0.001) and quality of life (ß estimate, 0.513; P < 0.001) were the only significant correlates for group membership. For the group 3 TPA trajectory, male sex (ß estimate, 1.970; P = 0.035), greater household income (ß estimate, 94.615; P < 0.001), and greater parental total PA (ß estimate, 0.574; P = 0.023) increased the probability of belonging to this trajectory group. CONCLUSIONS: These findings suggest a need for interventions and public health campaigns to increase opportunities for PA engagement in girls starting in the early years. Policies and programs to address financial inequities, positive parental modeling, and improving quality of life are also warranted.


Assuntos
Exercício Físico , Qualidade de Vida , Criança , Feminino , Pré-Escolar , Humanos , Masculino , Pais , Relações Pais-Filho , Instituições Acadêmicas , Acelerometria
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