Fragile X syndrome (FXS) is a common form of inherited intellectual disability and is one of the leading known causes of autism. The mutation responsible for FXS is a large expansion of the ...trinucleotide CGG repeat in the 5' untranslated region of the X-linked gene FMR1. This expansion leads to DNA methylation of FMR1 and to transcriptional silencing, which results in the absence of the gene product, FMRP, a selective messenger RNA (mRNA)-binding protein that regulates the translation of a subset of dendritic mRNAs. FMRP is critical for mGluR (metabotropic glutamate receptor)-dependent long-term depression, as well as for other forms of synaptic plasticity; its absence causes excessive and persistent protein synthesis in postsynaptic dendrites and dysregulated synaptic function. Studies continue to refine our understanding of FMRP's role in synaptic plasticity and to uncover new functions of this protein, which have illuminated therapeutic approaches for FXS.
The current study examined associations between gender, perceived athletic competence, and enjoyment of physical education (PE) class over time in a cohort of children enrolled in grade four (ages 9 ...or 10) at baseline (n = 2262).
We assessed each student 5 times over a period of 2 years. We used mixed effects modeling to examine change over time in enjoyment of PE.
Enjoyment of PE declined among girls but remained constant among boys. Higher levels of perceived competence were associated with higher PE enjoyment. A 3-way interaction between gender, competence, and time revealed that PE enjoyment was lowest and declined most markedly among girls with low perceived athletic competence. Among boys with low competence, enjoyment remained at a consistently low level.
Our results indicate that lower perceived athletic competence is associated with low enjoyment of PE, and, among girls, with declining enjoyment. Findings suggest that interventions in a PE context that target perceived competence should be considered in future work.
Current research investigating the relationship between mental fatigue and physical activity behaviors relies on laboratory-based, experimental studies which lack ecological validity.
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.
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.
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).
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.
•Higher mental fatigue than one’s average is associated with lower motivation and fewer MVPA minutes.•Lower motivation than one’s average is associated with fewer MVPA minutes.•No between-person effects were observed for mental fatigue and motivation on MVPA.•Decomposing between- and within-person effects is needed to understand real-time behaviors.
An emerging body of the literature in the past two decades has generally shown that prior cognitive exertion is associated with a subsequent decline in physical performance. Two parallel, but ...overlapping, bodies of literature (i.e., ego depletion, mental fatigue) have examined this question. However, research to date has not merged these separate lines of inquiry to assess the overall magnitude of this effect.
The present work reports the results of a comprehensive systematic review and meta-analysis examining carryover effects of cognitive exertion on physical performance.
A systematic search of MEDLINE, PsycINFO, and SPORTDiscus was conducted. Only randomized controlled trials involving healthy humans, a central executive task requiring cognitive exertion, an easier cognitive comparison task, and a physical performance task were included.
A total of 73 studies provided 91 comparisons with 2581 participants. Random effects meta-analysis showed a significant small-to-medium negative effect of prior cognitive exertion on physical performance (g = - 0.38 95% CI - 0.46, - 0.31). Subgroup analyses showed that cognitive tasks lasting < 30-min (g = - 0.45) and ≥ 30-min (g = - 0.30) have similar significant negative effects on subsequent physical performance. Prior cognitive exertion significantly impairs isometric resistance (g = - 0.57), motor (g = - 0.57), dynamic resistance (g = - 0.51), and aerobic performance (g = - 0.26), but the effects on maximal anaerobic performance are trivial and non-significant (g = 0.10). Studies employing between-subject designs showed a medium negative effect (g = - 0.65), whereas within-subject designs had a small negative effect (g = - 0.28).
Findings demonstrate that cognitive exertion has a negative effect on subsequent physical performance that is not due to chance and suggest that previous meta-analysis results may have underestimated the overall effect.
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.
It has been theorized that physical literacy is associated with physical activity and health. The purpose of this study is to investigate the associations between physical literacy and health, and if ...this relationship is mediated by moderate-to-vigorous physical activity (MVPA). Two hundred and twenty-two children (113 girls, 10.7 ± 1.0 years old) participated in this cross-sectional study. A physical literacy composite score was computed from measures of PLAYfun, PLAYparent, and PLAYself. Physical activity was measured over seven days with accelerometers, expressed as MVPA (min/day). Health indicators included: body composition (percent body fat), aerobic fitness (treadmill time and 60s heart rate recovery), resting systolic blood pressure, and quality of life. Physical literacy was significantly associated (p < 0.001) with percent body fat (R2 = 0.23), treadmill time (R2 = 0.21), 60 s heart rate recovery (R2 = 0.36), systolic blood pressure (R2 = 0.11), and quality of life (R2 = 0.11). The relationships between physical literacy and aerobic fitness, but not other health indicators, were directly mediated by MVPA. Higher physical literacy in children is associated with favorable health indicators, and the relationships between physical literacy and aerobic fitness were influenced by MVPA. Future work should examine these relationships longitudinally and determine if changes in physical literacy leads to changes in health.
Fragile X syndrome (FXS) is a trinucleotide repeat disorder caused by a CGG repeat expansion in FMR1 , and loss of its protein product FMRP. Recent studies have provided increased support for the ...role of FMRP in translational repression via ribosomal stalling and the microRNA pathway. In neurons, particular focus has been placed on identifying the signaling pathways such as PI3K and mTOR downstream of group 1 metabotropic glutamate receptors (mGluR1/5) that regulate FMRP. New evidence also suggests that loss of FMRP causes presynaptic dysfunction and abnormal adult neurogenesis. In addition, studies on FXS stem cells especially induced pluripotent stem (iPS) cells and new sequencing efforts hold out promise for deeper understanding of the silencing process and mutation spectrum of FMR1.
The purpose of the present review was to provide a theoretical understanding of the learning advantages underlying a self-controlled practice context through the tenets of the self-determination ...theory (SDT). Three micro-theories within the macro-theory of SDT (Basic psychological needs theory, Cognitive Evaluation Theory, and Organismic Integration Theory) are used as a framework for examining the current self-controlled motor learning literature. A review of 26 peer-reviewed, empirical studies from the motor learning and medical training literature revealed an important limitation of the self-controlled research in motor learning: that the effects of motivation have been assumed rather than quantified. The SDT offers a basis from which to include measurements of motivation into explanations of changes in behavior. This review suggests that a self-controlled practice context can facilitate such factors as feelings of autonomy and competence of the learner, thereby supporting the psychological needs of the learner, leading to long term changes to behavior. Possible tools for the measurement of motivation and regulation in future studies are discussed. The SDT not only allows for a theoretical reinterpretation of the extant motor learning research supporting self-control as a learning variable, but also can help to better understand and measure the changes occurring between the practice environment and the observed behavioral outcomes.
Cardiovascular disease prevention should begin in childhood. However, the influence of physical activity on cardiovascular health in early childhood is unknown. Our purpose in this study was to ...determine the effect of physical activity on trajectories of cardiovascular health indicators during early childhood.
This prospective, observational cohort study (Health Outcomes and Physical Activity in Preschoolers) enrolled 418 3- to 5-year-olds with annual assessments for 3 years. Total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) were measured over 7 days via accelerometry. Cardiovascular health indicators included cardiovascular fitness (exercise time on a maximal treadmill test treadmill time and 1-minute heart rate recovery), resting arterial stiffness (whole-body pulse wave velocity and carotid β stiffness index), and seated systolic blood pressure. Data were analyzed by using linear mixed-effects modeling; effects are reported as unstandardized estimates (Est).
There were main effects of TPA and MVPA on treadmill time (Est = 0.004
= .005 and 0.008
= .001, respectively) and heart rate recovery (Est = 0.05
< .001 and 0.08
< .001, respectively). There was a main effect of TPA on pulse wave velocity (Est = -0.001;
= .02) and an MVPA × time interaction (Est = -0.002;
= .01). For carotid β stiffness index, the effect of a TPA × time interaction was not significant (Est = -0.002;
= .051); however, there was a significant MVPA × time interaction (Est = -0.003;
= .03). MVPA was associated with a slower rate of change in systolic blood pressure for girls (Est = 0.06;
= .009).
Children who engage in higher levels of physical activity during early childhood have better cardiovascular health indicators, with more intense physical activity (ie, MVPA) attenuating the stiffening of arteries.
Abstract
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.
Mental fatigue alters the amount of physical effort people plan to invest in an exercise workout and follow through with those intentions by doing less work and exercising at a lower heart rate.
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