Hysteresis behaviour of psychobiological variables during exercise

ObjectivesThe rating of perceived exertion (RPE) and the heart rate (HR) have been widely studied and monitored during exercise, but their hysteresis behaviour is still unexplored. Our aim was to study the hysteresis behaviour of RPE and HR in triathletes and non-athletes.DesignCross-sectional study.MethodEighteen triathletes at different competitive levels (elite n = 9, non-elite n = 9) and ten students were tested while cycling and running, using a pyramidal protocol (incremental/decremental workloads). The hysteresis area, considered positive when values of the dependent variables (RPE and HR) at the same workload were higher in the decremental phase than in the incremental phase, and vice versa for the negative areas, was calculated in all tests. The Wilcoxon matched-pairs test and Kruskal Wallis ANOVA were applied to detect intra- and inter-group differences, respectively, of RPE and HR values during the incremental and decremental phases, as well as between cycling and running.ResultsThe following results were observed: a) an incoherent relationship of RPE with HR and workload, b) positive hysteresis areas of RPE and HR in all groups during cycling and running, c) a partial negative hysteresis area of RPE, but not of HR, in the triathlete groups, d) larger hysteresis areas of RPE and HR in students than in triathletes, and e) larger hysteresis areas in cycling than in running.Conclusionsthe study of the hysteresis behaviour of RPE and HR reveals the history dependency of both variables, highlights their incoherent or non-unique relationship during a pyramidal exercise, and questions their widely assumed linear association to workload intensity. The hysteresis area is proposed as a new non-invasive marker of exercise stress and tolerance that should be further investigated.     

On the bike and in the cubicle: The role of passion and regulatory focus in cycling and work satisfaction

ObjectivesTo examine the relationships between cycling passion and satisfaction with cycling and work. First we examine the how two types of passion for cycling (harmonious and obsessive) differentially affect cycling satisfaction. Second, we examine how a passion for cycling can have a spillover effect on work satisfaction. Third, we examine the mediating role of regulatory focus on the relationship between passion and satisfaction.DesignCross-sectional study of U.S. competitive cyclists using an online survey.MethodsSelf-reports of study variables were collected from 119 competitive cyclists, who were also employed in work roles beyond their cycling pursuits. Structural equation modeling techniques were used to examine the relationships between passion, regulatory focus, and satisfaction.ResultsResults from our sample indicate that while holding a harmonious passion for cycling positively relates to both cycling and work satisfaction, an obsessive passion results in diminished work satisfaction. Moreover, results from our mediation analysis indicate that regulatory focus partially mediates the relationships between harmonious passion and both cycling and work satisfaction.ConclusionsThese findings illustrate that not all forms of passion are beneficial to one's pursuits, demonstrate the potential spillover effect of pursuing one's passion for sport and its influence on work satisfaction, and suggest that regulatory focus helps explain the relationship between passion and satisfaction.     

Graduate programs: The Boulder Graduate School

Abstract

The motion picture is conceived of as a modern‐day avenue for providing humans with mythological, metaphorical and symbolic imagery. Human subjects were interviewed to determine how film imagery was processed on a cognitive basis. Subjects were also interviewed about their dream imagery to elicit any matching or resonating with the imagery from their felt film experience and dream experience. Utilizing a mythic method, the researcher examined the narratives to discover emergent patterns and configurations of symbolic imagery, metaphorical and mythological content as related to personal mythologies.     

Nano-undulations of nickel thin films on a substrate under compressive stress

Nickel thin films on a substrate have been studied in situ by atomic force microscopy during deformation. Undulations have been observed on the debonding regions, of very low amplitude and of periodicity of the order of 1mum. Attempts are made to compare these experimental results with previous models of buckling instabilities of thin plates.     

On the role of lyrics in the music–exercise performance relationship

ObjectivesTo examine the role of lyrics on a range of psychological, psychophysical, and physiological variables during submaximal cycling ergometry.DesignWithin-subject counterbalanced design.MethodTwenty-five participants performed three 6-min cycling trials at a power output corresponding to 75% of their maximum heart rate under conditions of music with lyrics, same music without lyrics, and a no-music control. Cycling cadence, heart rate, and perceived exertion were recorded at 2-min intervals during each trial. Positive and negative affect was assessed before and after each trial.ResultsParticipants cycled at a higher cadence towards the end of the cycling trials under music with lyrics. Main effects were found for perceived exertion and heart rate, both of which increased from min 2 through to min 6, and for affect: positive affect increased and negative affect decreased from pre- to post-trials.ConclusionsParticipants pedalled faster in both music conditions (with and without lyrics) while perceived exertion and heart rate did not differ. The inclusion of lyrics influenced cycling cadence only at min 6 and had no effect on the remaining dependent variables throughout the duration of the cycling trials. The impact of lyrical content in the music–exercise performance relationship warrants further attention in order for us to better understand its role.     

Mental health consequences of weight cycling in the first-year post-treatment for breast cancer

Objectives: Weight cycling is linked with advanced breast cancer diagnosis, increased risk of cancer reoccurrence and cancer-related mortality. While women treated for breast cancer report challenges with navigating their post-treatment body shape and weight, the effects of weight cycling on body image and mental health have not been elucidated. This study examined associations between weight changes and weight cycling on psychological health (i.e. weight-related guilt, shame and depressive symptoms) among women in the first-year post-treatment.

Design and Outcome Measures: Self-reported assessments of pre-cancer weight cycling, post-treatment weight-related guilt, shame and depressive symptoms, and objective assessments of weight were assessed in a longitudinal sample of 173 women treated for breast cancer (M_age = 55.01 ± 10.96 years).

Results: Based on findings from multilevel models, women experienced the most weight-related shame when their weight was heavier than their personal average. Additionally, heavier weight was associated with worse psychological health, particularly for women with a history of stable (vs. cycling) weight pre-cancer.

Conclusions: Weight cycling pre-cancer and post-treatment weight change have important implications for psychological well-being. Due to the potential psychological consequences associated with a history of weight cycling, targeted strategies are needed to improve overall health outcomes for women’s survivorship after breast cancer.     

Fluctuating dynamics of perceived exertion in constant-power exercise

ObjectivesTo reveal and study the fluctuating dynamics of perceived exertion (PE) during constant-power exercise performed under different conditions (duration, intensity, and termination).DesignA pilot and two subsequent experimental studies were performed. The studies consisted of manipulating workload and measuring fluctuating perceived exertion dynamics throughout the cycling task.MethodsIn a pilot study Borg's rating of perceived exertion (RPE) was measured every 15 s in 2 groups of 9 participants each (using RPE 6-20 and CR10 scales, respectively) cycling at heavy intensity until volitional exhaustion. The percentage of participants alternating increased and decreased RPE values (fluctuating dynamics) was calculated. In 2 subsequent experiments PE changes (increase/decrease perceptions) were reported when occurring in 2 groups of 13 participants cycling at a moderate intensity for 30 and 60 min, respectively (Experiment 1), and in another group of 12 participants cycling at heavy intensity until volitional exhaustion (Experiment 2). The individual time series of “increase”/“decrease” reports were divided into 5 non-overlapping temporal windows, and the percentages of “PE increase” were calculated for each window.ResultsIn the pilot study 66.6% (RPE 6-20 group) and 33.3% (CR10 group) of the participants showed an RPE fluctuating dynamics during the exercise. However, all participants showed a clear PE fluctuating dynamics during the moderate and heavy intensity exercises performed in Experiment 1 and Experiment 2, respectively. Nevertheless, a transition towards a PE non-fluctuating dynamics (dominated by “PE increase” reports) was noticed in Experiment 2 while approaching volitional exhaustion.ConclusionsPE seems to have a dominant fluctuating dynamics during constant-power cycling performed under different conditions (duration, intensity, and termination) that changes towards a non-fluctuating dynamics when approaching the volitional exhaustion point.     

Effects of Hormone Replacement Therapy and Aging on Cognition: Evidence for Executive Dysfunction

ABSTRACT

The present study was designed to explore whether the frontal lobe hypothesis of cognitive aging may be extended to describe the cognitive effects associated with estrogen use in postmenopausal women. Postmenopausal estrogen-only users, estrogen + progesterone users, and non-users (60–80 years old), as well as young, regularly cycling women (18–30 years old) completed an item and source memory task. Since source memory is thought to rely more on executive processes than item memory, we hypothesized that aging and estrogen effects would be greater for source memory than for item memory. Neuropsychological tests explored whether the effects of aging and estrogen use were revealed on other tests of frontal lobe function. Results from the experimental task revealed greater aging and estrogen effects for source memory than for item memory, and neuropsychological results revealed aging and estrogen effects on a subset of tests of executive function. Women on estrogen + progesterone therapy did not outperform non-users, suggesting that the addition of progesterone to hormone therapy may mitigate the benefits induced by estrogen use alone. Overall, findings support the hypothesis that estrogen use may temper age-related cognitive decline by helping to maintain functions subserved by the frontal lobes.     

Differences in parental perceptions of walking and cycling to high school according to distance

BackgroundParental perceptions towards different modes of transport correlate with adolescents’ mode choice for school trips. Whether parental attitudes differ for walking versus cycling and/or home-to-school distance is unknown. We compared parental perceptions of walking versus cycling to school in adolescents in Dunedin, New Zealand and examined whether mode-specific barriers differ by distance to school.MethodsParents (n = 341; age: 47.5 ± 5.2 years; 77.1% females) completed a survey about their adolescent’s (age: 13–18 years; 48.1% boys) school travel and their own perceptions of walking/cycling to school. Participants were categorised into three groups according to distance to school as ‘walkable’ (≤2.25 km), ‘cyclable’ (>2.25–≤4.0 km) and ‘beyond cyclable’ (>4.0 km).ResultsCommon modes of transport to school differed significantly across the ‘walkable’/’cyclable’/’beyond cyclable’ categories (car passenger: 25.7%/40.5%/60.6%; public/school bus: 5.5%/15.4%/28.4%; walking: 66.2%/28.2%/1.2%; cycling: 0.0%/7.7%/0.5%; all p < 0.001). Compared to walking, parents perceived cycling to school to be less important (walking/cycling: 87.5%/62.5%), with less social support from parents (46.2%/17.1%), peers (20.6%/4.8%) and school (24.5%/12.4%), less interest from adolescents (48.5%/31.9%), fewer cycle paths (26.5%) versus footpaths (65.0%) and more safety concerns (35.0%/64.6%; all p < 0.001). As distance to school increased, parents’ social support decreased whereas personal, environmental and safety-related barriers increased for both modes, with less consistent findings for cycling. Overall, 68.2% of parents expected to participate in adolescents’ walking/cycling to school decision-making.ConclusionsParents favoured walking compared to cycling to school with parental attitudes for both modes changing with increasing distance to school. The findings illustrate the importance of addressing parental concerns, considering the specificity of walking and cycling and taking into account distance to school in active transport to school initiatives.     

Cycling outdoors facilitates external thoughts and endurance

ObjectivesThe aims of this study were twofold: (a) to compare the effects of indoor and outdoor environments on cycling endurance and thought dynamics, (b) to investigate a possible link between cycling endurance and the adherence to task-unrelated thoughts (TUT) in both environments. Design: An experimental, within-subject design with two-trial random assignment was used.MethodsParticipants (n = 13) cycled at constant power until volitional exhaustion while imposing TUT. They reported thought changes using self-selected key words that were subsequently classified based on task-relatedness (TUT, and task-related thoughts (TRT)) and direction (internal, external). Mean values of relative time spent in TUT and TRT categories were computed and compared for 5 equal time intervals. The association between cycling endurance and time spent at each thought-related category was analyzed.ResultsAnalyses revealed a decrease of TUT and an increase of TRT as a function of time (spent cycling) in both environments. Three qualitative thought phases emerged: an initially stable TUT phase was followed by a metastable phase characterized by shifts between TUT and TRT, and a final stable TRT phase appeared nearing exhaustion. Participants cycled longer outdoors than indoors M_outdoors = 12.54 min, SEM = 2.17 s, M_indoors = 11.35 min, SEM = 1.52 s (Z = −2.27, p < 0.05, d(95% CI) = 0.56 (−0.80, 3.07)), with a dominance of external thought categories. Cycling endurance seemed to be facilitated by TUT-E outdoors and TRT-I in both types of environments.ConclusionOutdoor environment resulted in improved cycling endurance and greater use of external thoughts (i.e., dissociative attentional strategy) relative to indoor environment. The effectiveness of thought categories seemed contingent upon their stability, which in turn depended on effort accumulation.     

Attention focus during physical effort: The mediating role of task intensity

ObjectivesTenenbaum's (2001) [A social-cognitive perspective of perceived exertion and exertion tolerance. In R. N. Singer, H. Hausenblas, & C. Janelle (Eds.), Handbook of sport psychology (pp. 810–820). New York, NY:Wiley] exercise intensity-attention linkage model was used to design and carry out two studies to examine individuals’ attentional strategies during engagement in two physically demanding tasks, and the mediating effect of task intensity on attention focus.DesignAn experimental design was employed where thought classifications (associative vs. dissociative) during three stages of a handgrip task (study 1) and during 50%, 70%, and 90% VO₂ max effort in a cycling task (study 2) were subjected to non-parametric Chi-square analysis.MethodsMale and female participants were exposed to the increasing sensation of physical effort via two fatiguing tasks: an isometric handgrip task (n=35), and a stationary cycling task (n=13). During each task participants were instructed to vocally express their current thoughts—in sentences, phrases or words—continuously throughout the testing procedure. Participant's self-reported thoughts were recorded during the tasks, and later classified to reveal patterns of associative and dissociative attention focus.ResultsAttention focus was predominantly associative when task intensity was high. These findings are consistent with Tenenbaum's (2001) [A social-cognitive perspective of perceived exertion and exertion tolerance. In R. N. Singer, H. Hausenblas, & C. Janelle (Eds.), Handbook of sport psychology (pp. 810–820). New York, NY:Wiley] model postulating the relationship between exercise intensity and attention allocation, which maintains that above a given effort threshold physiological cues dominate attention focus.ConclusionsDuring conditions of high workload and prolonged duration, attention is focused on overwhelming physiological sensations, which dominate focal awareness. At this point an associative attention focus is almost unavoidable.     

The Virtual Kitchen Challenge: preliminary data from a novel virtual reality test of mild difficulties in everyday functioning

ABSTRACT

Background: Efficient, objective measures of mild functional difficulties are lacking. Preliminary data from a novel, non-immersive virtual reality, performance-based task (Virtual Kitchen Challenge; VKC) were obtained to address this gap.

Methods: 14 older and 21 younger adults completed cognitive tests and two everyday tasks (breakfast, lunch) in the VKC with virtual objects and a touch-screen and in the Real Kitchen with real objects (order counterbalanced). Automated performance measures were obtained from the VKC program and human coders scored VKC and Real Kitchen videos for errors.

Results: Older adults made more errors than younger adults on the VKC and Real Kitchen, with similar error patterns across measures. VKC automated measures were significantly related to measures from human coders, performance on the Real Kitchen, and cognitive test scores.

Conclusion: The VKC is a valid and highly efficient performance-based measure of subtle functional difficulties with great potential for future clinical and research applications.     

The relationship between suppression and subsequent intrusions: the mediating role of peritraumatic dissociation and anxiety

Background and objectives: Although previous studies showed that thought and emotion suppression represent risk factors for intrusions development, the mechanisms that explain these relations were less explored. This study aims to examine the relationships between thought and emotion suppression and the symptoms of intrusion following the exposure to a trauma-related event. Moreover, we explored if these relationships would be mediated by peritraumatic state dissociation and state anxiety.

Design and methods: The trauma film paradigm was used and the participants were students (N?=?148) experimentally exposed to an aversive film to model a traumatic experience. Thought and emotion suppression were measured before the trauma exposure. After exposure, the participants completed scales for measuring state dissociation and state anxiety. Intrusive images and thoughts of the film were recorded in the subsequent week using an intrusion diary.

Results: Thought suppression predicted intrusive thoughts frequency, and this effect was mediated by the peritraumatic anxiety. State anxiety predicted both intrusive images and thoughts, while state dissociation only predicted intrusive images.

Conclusions: Intrusive images and intrusive thoughts are different phenomena and they are predicted by different variables. The practical implications of these results for posttraumatic stress disorder treatment and secondary traumatization are discussed.     

Sex differences in cognition in healthy elderly individuals

ABSTRACT

Sex differences in patterns of cognitive test performance have been attributed to factors, such as sex hormones or sexual dimorphisms in brain structure, that change with normal aging. The current study examined sex differences in patterns of cognitive test performance in healthy elderly individuals. Cognitive test scores of 957 men and women (age 67–89), matched for overall level of cognitive test performance, age, education, and depression scale score, were compared. Men and women were indistinguishable on tests of auditory divided attention, category fluency, and executive functioning. In contrast, women performed better than men on tests of psychomotor speed and verbal learning and memory, whereas men outperformed women on tests of visuoconstruction and visual perception. Our finding that the pattern of sex differences in cognition observed in young adults is observed in old age has implications for future studies of both healthy elderly individuals and of those with cognitive disorders.     

Group cycling safety behaviours: A systematic review

BackgroundThe popularity of cycling in a group is longstanding and increasing. Compared to riding as an individual, many cyclists feel safer when riding in a group as they have better personal security, potential support in case of mishaps, safer wayfinding and are more visible to other road users. However, further to the safety challenges shared with individual cyclists, group cyclist safety is impacted by rider proximity, the larger space taken up on roadways, potentially higher speeds, and social norms that could increase risky behaviours. Despite these unique safety considerations, the practice of cycling in groups has received little academic attention and group cyclist safety behaviours have not been analysed by road safety researchers.ObjectiveTo identify, describe, categorise and conceptualise within a teamwork framework, safety related behaviours of groups of cyclists as mentioned in academic literature.MethodsThree academic databases (Google Scholar, Proquest, and Scopus) were searched for peer reviewed literature that mentioned safe or risky behaviours of groups of cyclists. A total of 32 papers met the inclusion criteria. Relevant group cyclist behaviours were described and categorised using a conceptual teamwork framework.ResultsGroup cyclists’ safety behaviours are governed by a comprehensive but informal and adaptable set of rules. These rules are safety critical and are often strictly controlled within groups. Many groups of cyclists may ride in a safer manner than individual cyclists due to teamwork factors, particularly shared mental models, team orientation, and adaptability.ConclusionGroup cyclists take safety seriously. Teamwork factors may make behavioural interventions to decrease risky behaviours easier to implement with group cyclists compared to individual cyclists. Investigation of group cycling safety behaviours may inform safe system interventions to increase road safety.     

Epitaxial Ni-Al thin films on NaCl using a Ag buffer layer

Epitaxial nanoscale [001] films of Ni _x Al_100-x (x = 62.5) have been prepared by physical vapour deposition on to a thin film of Ag [001] on NaCl (001) faces with occasional hillocks. The Ag film contains numerous dislocations and stacking faults and has a rms surface roughness of 2 nm. The Ni-Al film is ordered in the B2 structure and reveals many dislocations as well as antiphase boundaries between ordered domains. The formation of subgrains in the Ni-Al film results in severe height variations up to 30 nm across the surface. A cross-sectional model for the growth of both films is presented.     

Relation of motor,linguistic and temperament factors in epidemiologic subtypes of persistent and recovered stuttering: Initial findings

PurposeThe purpose of this study was to determine the presence of any patterns reflecting underlying subtypes of persistence and recovery across epidemiologic, motor, language, and temperament domains in the same group of children beginning to stutter and followed for several years.MethodsParticipants were 58 2–4-year-old CWS and 40 age and gender matched NFC from four different sites in the Midwest. At the end of the multi-year study, stuttering children were classified as Persistent or Recovered. The same protocol obtaining data to measure stuttering, motor, language and temperament characteristics was used at each site. They have not been included in previous reports.ResultsThe Persistent group performed consistently differently from the Recovered and Control groups. They performed lower on standardized language tests and in phonological accuracy, had greater kinematic variability, and were judged by their parents to be more negative in temperament.ConclusionsThe present study provides data supporting the hypothesis that subtypes of stuttering can be identified along persistency/recovery lines, but results were not definitive.Educational Objectives: Readers will be able to (a) describe the current state of subtypes of stuttering research; (b) summarize possible contributions of epidemiologic, motoric, linguistic and temperament to such subtyping with regard to persistency and recovery.     

Visual scanning patterns and executive function in relation to facial emotion recognition in aging

ABSTRACT

Objective: The ability to perceive facial emotion varies with age. Relative to younger adults (YA), older adults (OA) are less accurate at identifying fear, anger, and sadness, and more accurate at identifying disgust. Because different emotions are conveyed by different parts of the face, changes in visual scanning patterns may account for age-related variability. We investigated the relation between scanning patterns and recognition of facial emotions. Additionally, as frontal-lobe changes with age may affect scanning patterns and emotion recognition, we examined correlations between scanning parameters and performance on executive function tests. Methods: We recorded eye movements from 16 OA (mean age 68.9) and 16 YA (mean age 19.2) while they categorized facial expressions and non-face control images (landscapes), and administered standard tests of executive function. Results: OA were less accurate than YA at identifying fear (p < .05, r = .44) and more accurate at identifying disgust (p < .05, r = .39). OA fixated less than YA on the top half of the face for disgust, fearful, happy, neutral, and sad faces (p values < .05, r values ≥ .38), whereas there was no group difference for landscapes. For OA, executive function was correlated with recognition of sad expressions and with scanning patterns for fearful, sad, and surprised expressions. Conclusion: We report significant age-related differences in visual scanning that are specific to faces. The observed relation between scanning patterns and executive function supports the hypothesis that frontal-lobe changes with age may underlie some changes in emotion recognition.     

Formation and hydrogen adsorption properties of Ti-Hf-Ni quasicrystals and crystal approximants

The formation of a high-order rational approximant (RA) phase in rapidly quenched Ti-Hf-Ni alloys and the hydrogen absorption properties of that phase are reported. Electron diffraction patterns show systematic shifts of the diffraction spots from their expected positions for the icosahedral phase (i-phase); the diffraction patterns are consistent with those expected for a 3/2 RA phase RA-(Ti-Hf-Ni). Based on differential scanning calorimetry studies, RA-(Ti-Hf-Ni) is metastable, transforming between 350 and 500°C to a quasicrystal with strong phason disorder. This crystallizes at 620°C to a Ti 2 Nitype phase. RA-(Ti-Hf-Ni) readily absorbs hydrogen, up to 1.2 hydrogen atoms per metal atom ([H][M] =1.2). Pressure-composition isotherm studies for gasphase loading show that the pressure plateau for RA-(Ti-Hf-Ni) is similar to that observed for the i-(Ti-Zr-Ni) phase, although it occurs at as lightly higher pressure and extends over a smaller range of hydrogen concentrations. Unlike i-(Ti-Zr-Ni), no irreversible hydride phase forms with hydrogen loading at 250°C, suggesting that RA-(Ti-Hf-Ni) may have superior cycling properties, of interest for hydrogen storage applications.     

Energy contributions in the martensitic transformation of shape-memory alloys

Abstract

The thermoelastic martensitic transformation in shape-memory alloys is studied thermodynamically. Calorimetric experiments on the Cu─Zn─A1 alloy system reveal that the transformation takes place with a practically negligible entropy production. The usual hysteretic subloop behaviour during partial cycling is obtained for the first time by calorimetry. An analysis of the measurements gives the quantitative behaviour of elastic and dissipative energies with the volume fraction of martensite.