Effect of low-and high-carbohydrate diets on swimming economy: A crossover study
Background: Swimming economy refers to the rate of energy expenditure relative to swimming speed of movement, is inversely related to the energetic cost of swimming, and is as a key factor influencing endurance swimming performance. The objective of this study was to determine if high-carbohydrate, low-fat (HCLF) and low-carbohydrate, high-fat (LCHF) diets affect energetic cost of submaximal swimming.
Methods: Eight recreational swimmers consumed two 3-d isoenergetic diets in a crossover design. Diets were tailored to individual food preferences, and macronutrient consumption was 69-16-16% and 16-67-18% carbohydrate-fat-protein for the HCLF and LCHF diets, respectively. Following each 3-d dietary intervention, participants swam in a flume at velocities associated with 50, 60, and 70% of their maximal aerobic capacity (VO2max). Expired breath was collected and analyzed while they swam which enabled calculation of the energetic cost of swimming. A paired t-test compared macronutrient distribution between HCLF and LCHF diets, while repeated-measures ANOVA determined effects of diet and exercise intensity on physiological endpoints.
Results: Respiratory exchange ratio was significantly higher in HCLF compared to LCHF (p = 0.003), but there were no significant differences in the rate of oxygen consumption (p = 0.499) or energetic cost of swimming (p = 0.324) between diets. Heart rate did not differ between diets (p = 0.712), but oxygen pulse, a non-invasive surrogate for stroke volume, was greater following the HCLF diet (p = 0.029).
Conclusions: A 3-d high-carbohydrate diet increased carbohydrate utilization but did not affect swimming economy at 50-70% VO2max. Although these intensities are applicable to ultramarathon swims, future studies should use higher intensities that would be more relevant to shorter duration events.
© Copyright 2020 Journal of the International Society of Sports Nutrition. Taylor & Francis. Kaikki oikeudet pidätetään.
Aiheet: | ravitsemus hiilihydraatti energia-aineenvaihdunta suhde tehokkuus suorituskyky uinti |
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Aihealueet: | biologiset ja lääketieteelliset tieteet kestävyys urheilu |
Tagging: | Makronährstoff |
DOI: | 10.21203/rs.3.rs-39435/v1 |
Julkaisussa: | Journal of the International Society of Sports Nutrition |
Julkaistu: |
2020
|
Painos: | 02. Juli 2020 |
Vuosikerta: | 17 |
Numero: | 1 |
Sivuja: | Article 64 |
Julkaisutyypit: | artikkeli |
Kieli: | englanti (kieli) |
Taso: | kehittynyt |