Influences of a Cold and Warm Environment on Substrate Metabolism in Women during Running and Cycling
Notice bibliographique
Résumé
Background Women oxidize more fat than men at rest and during exercise due to differences in hormonal and blood flow regulatory mechanisms, as well as substrate storage and mobilization. Exercise studies examining the effects of varying environments on energy metabolism have consistently demonstrated a greater shift towards lipid utilization in cold compared to warm environments in men. In addition, these studies have been conducted at fixed exercise intensities and workloads only, and have not been validated with different exercise modalities. Thereby, this study aimed to determine whether cold and warm ambient temperatures influence fat and CHO oxidation across a range of exercise intensities during treadmill and cycle ergometer exercise in women. Methods Twelve women (age 22 ± 1.8 yrs, weight 61 ± 6.6 kg, height 1.6 ± 0.09 m, body fat 26 ± 4.7 %, FFM 45 ± 5.8 kg, body surface area 1.6 ± 0.12 m 2 , and V̇O 2 48 ± 5.1 mlO2·kg −1 ·min −1 ) completed four trials, one week apart, during which they performed an incremental peak oxygen consumption (V̇O 2peak ) test on a cycle ergometer or treadmill in a cold (5°C) or warm (35°C) environment. Cardiorespiratory and oxidation variables, including V̇O 2 , maximal fat oxidation rate (MFO), exercise intensity where MFO occurs (Fat max ), and relative contribution of lipids and carbohydrates (CHO) to total energy expenditure crossover point (CC) were assessed via indirect calorimetry. Lactate pre and post tests was also assessed. Analyses of variances and multiple linear regressions were performed. Results MFO was greater in the cold vs. warm for treadmill (0.51 ± 0.19 vs. 0.41 ± 0.14 g•min −1 ; p=0.04) but not during cycling (0.32 ± 0.14 vs. 0.23 ± 0.07 g•min −1 ; p=0.08). MFO was also greater during treadmill vs. cycling exercise, in both temperatures (0.46 ± 0.16 g•min −1 vs. 0.28 ± 0.11 g•min −1 ; p<0.001). Fat max was greater in the cold vs. warm within treadmill (63 ± 27 vs. 49 ± 22 % V̇O 2max ; p=0.02) but not cycling (41 ± 20 vs. 31 ± 12 % V̇O 2max ; p=0.16). CC was greater in the cold vs. warm within treadmill exercise (53 ± 20 vs. 39 ± 17% V̇O 2max ; p=0.04) but not during cycling (36 ± 12 vs. 28 ± 10% V̇O 2max ; p=0.19). Multiple linear regressions further revealed a strong influence of ambient temperature on lipids (p<0.001) and CHO (p<0.001) oxidation rates across exercise intensities. Conclusions Exercising in a cold environment increased MFO, Fat max , and CC during treadmill exercise in women but not during cycling. These results imply that ambient temperature influences energy metabolism over a wide range of exercise intensities during treadmill exercise in women, similarly to what is seen in men. The large variability in fat oxidation in the present results, similar to other studies, will need to be investigated further in both women and men. Support or Funding Information This work was supported by a Laurentian University Research Fund grant. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
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Comment cette classification a été obtenuedéplier
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Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| 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 ».