Muscle Activity, Mechanical Work and Efficiency at Ventilatory Threshold During Maximal and Sub-Maximal Treadmill Exercise
Notice bibliographique
Résumé
0192 PURPOSE: To examine the effects of maximal and sub maximal steady-state treadmill exercise on muscle recruitment and activation, their relationships with the mechanical work and efficiency. METHODS: A group of thirteen non-endurance trained male subjects were exposed to an incremental maximal treadmill test during which oxygen consumption and electromyography (EMG) were collected. Fortyeight hours following the maximal test, two 10-minute constant workload treadmill exercise at intensities of 20% above (supra-VT) and below (sub-VT) the ventilatory threshold (VT) determined during the VO2max test. During these two tests the oxygen consumption and the EMG were monitored. A digital video camera was used to capture individual motions during the max and the sub-max on treadmill. The subjects were also asked to run on a 10 meters platform passing through a force plate at the supra-VT and sub-VT speeds. The 4 sub maximal tests were randomly assigned and separated by at least 15 minutes of passive rest. RESULTS: The iEMGexercise intensity relationships showed a strong and significant correlation for each muscle monitored suggesting a linear relationship; r = 0.75, 0.86, 0.83 for the vastus lateralis (VL), biceps femoris (BF), and gastrocnemius lateralis (GL) respectively. Based on the subsequent findings of paired t-tests this relationship was found to have a threshold during the incremental test. Further this iEMG threshold was correlated (r = 0.81) to the ventilatory threshold (VT) as determined from metabolic parameters. A significant iEMG threshold was also noted in the VL during the supra-VT workload. The muscle activity during the incremental test was significantly greater than the muscle activity from the same muscle during the sub maximal workloads when matched for VO2, workload and respiratory exchange ratio (RER). The mechanical efficiency decreased as the intensity increased during the max test and the two sub max tests. CONCLUSIONS: The inability of the current study to determine the specific mechanism of the EMG thresholds despite the correlation with the VT, suggests that no conclusion can be made regarding the relationship that may exist between these 2 parameters. Although not clearly depicted in the current results, the activation of agonist muscles within each functional group of muscles of the lower limb is the likely mechanism of the discrepancies in muscle activation between the incremental and the constant workload exercises.
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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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
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 ».