Skeletal Muscle Metabolism during an Exercise Challenge pre and post Aerobic Training in Lean and Obese Middle-Aged Individuals
Notice bibliographique
Résumé
PURPOSE: To examine the effects of exercise intensity (40 and 60% VO2peak) on skeletal muscle metabolism in sedentary middle-aged lean and obese individuals, pre and post an 8 week aerobic training program. METHODS: Ten normal weight (lean) and eight obese (age, 41.0 ± 2.2 and 39.3 ± 4.7 yrs; body mass index, 24.7 ±0.7 and 36.1 ± 2.0 kg/m2; VO2peak, 40.5 ± 2.3 and 36.6 ±1.5 ml/min/kg fat free mass) volunteers cycled for 10 min at 40% VO2peak and 10 min at 60% VO2peak pre and post 8 wk of exercise training (60 min/d, 5 d/wk, 60% VO2peak). Muscle biopsies were taken from the vastus lateralis muscle at rest and following 40 and 60% of pre-training VO2peak and blood samples were obtained throughout exercise both pre and post training. RESULTS: Aerobic training improved VO2peak by ∼24 and 17% in the obese and lean groups. Muscle citrate synthase activity was similar between groups before training and increased by ∼50% in each group post training (lean, 81.5 ± 8.0 to 122.8 ± 7.9 and obese, 77.8 ± 5.7 to 118.4 ± 3.2 mmol/min/kg dm). ±-hydroxyacyl-CoA-dehydrogenase activity was also similar between groups before training and increased by ∼40% following training in each group (lean, 44.4 ± 2.2 to 61.3 ± 5.4 and obese, 47.3 ± 3.3 to 65.5 ± 4.5 mmol/min/kg dm). Exercise increased venous plasma epinephrine and whole blood lactate (La) at 60% VO2peak in both groups, with 2–3 fold higher increases in the obese group. Post training, the exercise-induced epinephrine and La increases were blunted in both groups but to a greater extent in the obese. There were no differences between groups in resting muscle La, phosphocreatine (PCr), Cr or ATP contents pre or post training. Muscle La increased during exercise at 60% VO2peak in both groups with a greater response in the obese (23.4 ± 2.9 vs. 39.9 ± 4.7 mmol/kg dm). Following training, the muscle La increase was blunted in both groups but to a larger extent in the obese. Prior to training, exercise at both power outputs decreased muscle PCr similarly in lean and obese groups (lean, 86.2 ± 3.6 to 71.4 ± 4.8 and 53.6 ±4.9 mmol/kg dm at 40 and 60%; obese, 83.9 ± 3.9 to 69.4 ± 6.0 and 48.7 ± 4.9 mmol/kg dm at 40 and 60% VO2peak). Following training there was no significant decrease in PCr at either exercise intensity in both groups. Muscle ATP content was unaffected by exercise in either group both pre and post training. CONCLUSION: Prior to aerobic training, exercise at the same relative low and moderate intensities elicited a greater whole body and skeletal muscle metabolic response in middle-aged obese vs. lean individuals. In response to aerobic training, the metabolic responses to exercise at the same pre-training power output were blunted in both groups, but to a greater extent in the obese.
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 | 0,000 | 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 ».