Notice bibliographique
Résumé
It is world knowledge that regular physical exercise increases physical fitness and reduces general health risk factors like overweight or hypertension. There is emerging evidence that regular physical exercise does also have profound effects on the brain: It affects many aspects of the brain like increasing perfusion or inducing hippocampal growth. Neurogenesis is stimulated as well as angiogenesis and increased synaptic plasticity is observed. Up to date, most data are mainly supported by animal models but human data become more and more available. There is also emerging evidence that exercise has an positive effect on pain processing: One can find anecdotal reports that runners continue to run despite stress fractures, angina and or sever blisters. But there is also experimental evidence, that athletes have increased pain thresholds and show reduced responses to noxious stimuli. Indirect measures such as raised endorphin levels in peripheral blood and cerebrospinal fluid as well as the reversibility of exercise-induced mood changes and pain perception effects by naloxone (unspecific opioid receptor antagonist) presented strong arguments for an opioidergic involvement in exercise („endorphin hypothesis”). This was also supported lately by showing opioidergic activation effects in fronto-limbic brain regions after sustained physical exercise. Based on this work and assuming central opioidergic mechanisms, we examined in an fMRI-study the effect of a two hours outdoor RUN, as compared to a control condition (two hours outdoor WALK) on pain processing in 20 right-handed male athletes (age 39.0±9.2 years, average training distance: 59.3±29.2km/week). Physical exercise was expected to affect pain processing on the behavioural and the systemic (activation) level. On the behavioural level we found a significant time x treatment interaction of the euphoria ratings, and a post-hoc significant reduction of the McGill affective subscale in the post-run condition. All other measures (including pain and sensory thresholds) were not affected. The peripheral blood endorphin levels were drastically elevated after the RUN-condition and the fMRI-analysis revealed a reduced time x treatment interaction in the antinociceptive pathway (rACC, PAG) and reduced functional connectivity of the PAG (trend). These findings suggest, that the brain seems to be in a less pain sensitive state after exercise and, therefore, the necessity to recruit the descending pain network is reduced. In conclusion, the demonstration of elevated beta-endorphin levels in plasma (RIA), the specific effect on the affective dimension of pain, and the loco-regional convergence with previous ligand PET and naloxone pharma-fMRI studies suggest an underlying opioidergic effect promoted by exercise.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,003 | 0,002 |
| Études des sciences et des technologies | 0,001 | 0,002 |
| Communication savante | 0,003 | 0,003 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,002 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,017 | 0,004 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».