Effects of a 4-Week Very Low-Carbohydrate Diet on High-Intensity Interval Training Responses.
J Sports Sci Med
; 17(2): 259-268, 2018 06.
Article
em En
| MEDLINE
| ID: mdl-29769827
ABSTRACT
The purpose of the study was to examine the effects of altering from habitual mixed Western-based (HD) to a very low-carbohydrate high-fat (VLCHF) diet over a 4-week timecourse on performance and physiological responses during high-intensity interval training (HIIT). Eighteen moderately trained males (age 23.8 ± 2.1 years) consuming their HD (48 ± 13% carbohydrate, 17 ± 3% protein, 35 ± 9% fat) were assigned to 2 groups. One group was asked to remain on their HD, while the other was asked to switch to a non-standardized VLCHF diet (8 ± 3% carbohydrate, 29 ± 15% protein, 63 ± 13% fat) for 4 weeks. Participants performed graded exercise tests (GXT) before and after the experiment, and an HIIT session (5x3min, work/rest 21, passive recovery, total time 34min) before, and after 2 and 4 weeks. Heart rate (HR), oxygen uptake (VÌO2), respiratory exchange ratio (RER), maximal fat oxidation rates (Fatmax) and blood lactate were measured. Total time to exhaustion (TTE) and maximal VÌO2 (VÌO2max) in the GXT increased in both groups, but between-group changes were trivial (ES ± 90% CI -0.1 ± 0.3) and small (0.57 ± 0.5), respectively. Between-group difference in Fatmax change (VLCHF 0.8 ± 0.3 to 1.1 ± 0.2 g/min; HD 0.7 ± 0.2 to 0.8 ± 0.2 g/min) was large (1.2±0.9), revealing greater increases in the VLCHF versus HD group. Between-group comparisons of mean changes in VÌO2 and HR during the HIIT sessions were trivial to small, whereas mean RER decreased more in the VLCHF group (-1.5 ± 0.1). Lactate changes between groups were unclear. Adoption of a VLCHF diet over 4 weeks increased Fatmax and did not adversely affect TTE during the GXT or cardiorespiratory responses to HIIT compared with the HD.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dieta com Restrição de Carboidratos
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Desempenho Atlético
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Fenômenos Fisiológicos da Nutrição Esportiva
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Treinamento Intervalado de Alta Intensidade
Limite:
Adult
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Humans
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Male
Idioma:
En
Revista:
J Sports Sci Med
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
República Tcheca