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Effect of the subjective intensity of fatigue and interoception on perceptual regulation and performance during sustained physical activity
Full text linkBackground
The subjective experience of fatigue impairs an individual’s ability to sustain physical endurance performance. However, precise understanding of the specific role perceived fatigue plays in the central regulation of performance remains unclear. Here, we examined whether the subjective intensity of a perceived state of fatigue, pre-induced through prior upper body activity, differentially impacted performance and altered perceived effort and affect experienced during a sustained, isometric contraction in lower body. We also explored whether (cardiac) interoception predicted the intensity of experienced perceptual and affective responses and moderated the relationships between constructs during physical activity.
Methods
Using a repeated-measures study design, thirty male participants completed three experimental conditions, with the intensity of a pre-induced state of fatigue manipulated to evoke moderate (MOD), severe (SEV) and minimal (control; CON) intensity of perceptions prior to performance of the sustained contraction.
Results
Performance of the sustained contraction was significantly impaired under a perceived state of fatigue, with reductions of 10% and 14% observed in the MOD and SEV conditions, respectively. Performance impairment was accompanied by greater perceived effort and more negative affective valence reported during the contraction. However, effects were limited to comparisons to CON, with no difference evident between the two experimental trials (i.e. MOD vs. SEV). Individuals’ awareness of their accuracy in judging resting heartbeats was shown to predict the subjective intensity of fatigue experienced during the endurance task. However, interoception did not moderate the relationships evident between fatigue and both perceived effort and affective valence.
Conclusions
A perceived state of fatigue limits endurance performance, influencing both how effortful activity is perceived to be and the affective experience of activity. Though awareness of interoceptive representations of bodily states may be important to the subjective experience of fatigue, interoception does not modulate the relationships between perceived fatigue and other perceptual (i.e. effort) and affective constructs
Developing an ecological approach to physical activity promotion in adults with Cystic fibrosis
Full text linkBACKGROUND: There are few examples of interventions designed to promote physical activity (PA) in adults with Cystic fibrosis (CF). Increasing levels of habitual PA may be more feasible and result in greater compliance than conventional exercise training inventions which give little or no attention to long-term PA behaviour. Despite this there is limited research exploring perceptions of PA among adults with CF. The study aimed to understand the ecological correlates of PA in adults with CF and to involve individuals with CF, their families (where applicable) and clinicians in a formative process to inform the development of an ecological approach to PA promotion in this population. METHODS: An iterative approach was utilised, whereby findings from earlier phases of the research informed subsequent phases. Semi-structured interviews were conducted to explore patients’ perceptions of PA, devised using the PRECEDE component of the PRECEDE-PROCEED model. Followed by, focus groups to discuss the perceived barriers, facilitators and opportunities for PA participation and how this information could inform the development and delivery of a PA intervention. Separate focus groups were conducted with individuals with CF (n = 11) and their families and CF MDT members. Thematic analysis was used to construct themes. RESULTS: Physical and mental wellbeing manifested as both barriers and facilitators of PA. CF is characterised by a progressive decline in physical function, which presents as a number of challenging symptoms and set-backs for an individual with CF. PA represents an opportunity for participants to slow the rate of this decline and manage the symptoms associated with the condition. Enjoyment was an important facilitator of PA. Exercise professionals and family reinforce PA behaviour, particularly during adolescence. CONCLUSIONS: PA promotion should form part of routine CF care with additional exercise professional support during adolescence
Multimodal exercise evaluation is needed to truly determine the functional consequences of altered skeletal muscle oxidative capacity in cystic fibrosis
Full text linkInternational audienc
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Characterization of acute responses and chronic adaptations to eccentric exercise and exploration of preventive strategies to reduce neuromuscular alterations : application to the downhill running model.
No full textLa survenue d'altérations neuromusculaires et musculo-tendineuses lors d'épreuves de course à pied de fond s'avère être délétère sur la capacité de performance d'endurance et la période de récupération des athlètes. Par ailleurs, la sévérité de ces perturbations peut être exacerbée par les caractéristiques du terrain, et plus particulièrement par la présence de dénivelé négatif. En course à pied de descente, l'amplitude plus importante de ces altérations est sous-tendue par la prédominance du régime de contraction excentrique à l'exercice. Dès lors, la course à pied de descente constitue un challenge pour les coureurs dans leur quête d'excellence athlétique, aussi bien à l'entraînement que lors d'épreuves compétitives. L'exploration de stratégies préventives, ayant pour objectif de mieux tolérer les sections de course à pied en descente, apparaît donc pleinement justifiée dans le domaine de l'optimisation des réponses adaptatives en course à pied. Dans ce contexte, une première analyse prospective de la littérature a focalisé sur l'exploration des stratégies de répétitions de sessions (c.-à-d., usage chronique de la course à pied en descente) et du port in situ de textiles vestimentaires à visée ergogénique (e.g., textiles de compression et réflecteurs de rayons infrarouges lointains). Étant donné que l'usage chronique de la course à pied en descente pourrait également permettre l'instauration d'adaptations bénéfiques sur la capacité de performance des athlètes, il convenait au préalable de préciser les adaptations neuromusculaires et musculo-tendineuses à l'entraînement de course à pied en descente. Ainsi, les objectifs du travail de thèse étaient de caractériser les adaptations neuromusculaires et musculo-tendineuses à l’entraînement de course à pied en descente d'une part, et d’enrichir nos connaissances sur l’apport de stratégies préventives dans le domaine de la course à pied de fond, d'autre part. Les résultats de ce travail ont montré que : (i) l'entraînement de course à pied en descente (4 semaines) peut instaurer de rapides adaptations neuromusculaires (e.g., gains de force, hypertrophie musculaire) et tendineuses (par exemple, augmentation de la raideur du tendon patellaire), sans pour autant atténuer la sévérité des perturbations neuromusculaires à l'issue d'une session de course à pied en descente ; (ii) que le port de textiles de compression à l'exercice peut exercer un « effet protecteur dynamique » sur les groupes musculaires compressés, sans pour autant atténuer les perturbations de la capacité de performance d’endurance des athlètes ; et (iii) que le port de textiles réflecteurs de rayons infrarouges à l’exercice pourrait générer certains effets ergogéniques mais que la compréhension de leurs effets reste à ce jour globalement limitée.The occurrence of neuromuscular and musculotendinous alterations during long-distance running events is deleterious to the endurance performance capacity and recovery period of athletes. Furthermore, the severity of these disturbances can be exacerbated by the characteristics of the terrain, and more particularly by the presence of negative gradients. In downhill running, the greater magnitude of these alterations is underpinned by the predominance of eccentric contractions during this mode of exercise. Consequently, downhill running represents a challenge for runners in their quest for athletic excellence, both in training and in competitive events. The exploration of preventive strategies, with the aim of better tolerating downhill running sections, therefore appears fully justified in the field of optimising adaptive responses in running. In this context, a first prospective analysis of the literature focused on the exploration of strategies for repeating exercise bouts (e.g. the chronic use of downhill running) and wearing innovative garments (i.e. compression garments and far-infrared emitting garments). Since the chronic use of downhill running could also promote beneficial adaptations to the performance capacity of athletes, it was necessary to clarify the neuromuscular and musculotendinous adaptations to downhill running training. Thus, the objectives of the PhD thesis were to characterise the neuromuscular and tendinous adaptations to downhill running training and to improve our understanding of the contribution of textile-based preventive strategies in the field of long-distance running. The results of this work showed that: (i) downhill running training (4 weeks) can induce rapid neuromuscular (e.g. strength gains, muscle hypertrophy) and tendon adaptations (e.g. increase in patellar tendon stiffness), but does not alleviate the severity of neuromuscular disturbances after a downhill running bout ; (ii) that the wearing of compression garments during exercise could exert a « dynamic protective effect » on compressed muscle groups during exercise; and (iii) that the wearing of far-infrared emitting garments during exercise could promote some ergogenic aids, but that the understanding of their physiological effects remains limited to date
Assessment of Peripheral Muscle Function in Cystic Fibrosis: Why and How?
No full textInternational audienc
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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