Contribution of central and peripheral adaptations to changes in maximal oxygen uptake following 4 weeks of sprint interval training.
Appl Physiol Nutr Metab
; 43(10): 1059-1068, 2018 Oct.
Article
em En
| MEDLINE
| ID: mdl-29733694
ABSTRACT
The current study examined the contribution of central and peripheral adaptations to changes in maximal oxygen uptake (VÌO2max) following sprint interval training (SIT). Twenty-three males completed 4 weekly SIT sessions (8 × 20-s cycling bouts at â¼170% of work rate at VÌO2max, 10-s recovery) for 4 weeks. Following completion of training, the relationship between changes in VÌO2max and changes in central (cardiac output) and peripheral (arterial-mixed venous oxygen difference (a-vO2diff), muscle capillary density, oxidative capacity, fibre-type distribution) adaptations was determined in all participants using correlation analysis. Participants were then divided into tertiles on the basis of the magnitude of their individual VÌO2max responses, and differences in central and peripheral adaptations were examined in the top (HI; â¼10 mL·kg-1·min-1 increase in VÌO2max, p < 0.05) and bottom (LO; no change in VÌO2max, p > 0.05) tertiles (n = 8 each). Training had no impact on maximal cardiac output, and no differences were observed between the LO group and the HI group (p > 0.05). The a-vO2diff increased in the HI group only (p < 0.05) and correlated significantly (r = 0.71, p < 0.01) with changes in VÌO2max across all participants. Muscle capillary density (p < 0.02) and ß-hydroxyacyl-CoA dehydrogenase maximal activity (p < 0.05) increased in both groups, with no between-group differences (p > 0.05). Citrate synthase maximal activity (p < 0.01) and type IIA fibre composition (p < 0.05) increased in the LO group only. Collectively, although the heterogeneity in the observed VÌO2max response following 4 weeks of SIT appears to be attributable to individual differences in systemic vascular and/or muscular adaptations, the markers examined in the current study were unable to explain the divergent VÌO2max responses in the LO and HI groups.
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Base de dados:
MEDLINE
Assunto principal:
Oxigênio
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Consumo de Oxigênio
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Exercício Físico
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Metabolismo Energético
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Músculo Quadríceps
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Treinamento Intervalado de Alta Intensidade
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Contração Muscular
Limite:
Adult
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Humans
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Male
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article