No Cover Image

Journal article 249 views

Glycaemic Impact of Low‐ and High‐Glycaemic Index Carbohydrate Diets in Ultra‐Endurance Athletes: Insights From Continuous Glucose Monitoring

Ross Hamilton, RUIYANG XIA, Chloe Nicholas, Rachel Churm Orcid Logo, Olivia McCarthy, Richard Bracken Orcid Logo

European Journal of Sport Science, Volume: 25, Issue: 12, Start page: e70092

Swansea University Authors: Ross Hamilton, RUIYANG XIA, Chloe Nicholas, Rachel Churm Orcid Logo, Olivia McCarthy, Richard Bracken Orcid Logo

  • 70888.VOR.pdf

    PDF | Version of Record

    © 2025 The Author(s). European Journal of Sport Science published by Wiley-VCH GmbH on behalf of European College of Sport Science. This is an open access article under the terms of the Creative Commons Attribution License.

    Download (1.3MB)

Check full text

DOI (Published version): 10.1002/ejsc.70092

Abstract

Nine ultra-endurance athletes completed a randomised, crossover trial involving two 28-day dietary arms during which the athletes consumed a carbohydrate-rich diet (carbohydrate 58 ± 3, protein 15 ± 2 and fat 26 ± 2%) containing low- or high-glycaemic-index (LGI or HGI, respectively) carbohydrates....

Full description

Published in: European Journal of Sport Science
ISSN: 1746-1391 1536-7290
Published: Wiley 2025
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa70888
Abstract: Nine ultra-endurance athletes completed a randomised, crossover trial involving two 28-day dietary arms during which the athletes consumed a carbohydrate-rich diet (carbohydrate 58 ± 3, protein 15 ± 2 and fat 26 ± 2%) containing low- or high-glycaemic-index (LGI or HGI, respectively) carbohydrates. At the start and end of each dietary arm, participants performed a fasted 3-h submaximal run outdoors before ingesting either a low (GI = 32, isomaltulose [Palatinose]) or high (GI = 100, maltodextrin) glycaemic index drink (0.75 g/kg bm/h over 3.5 h). Participants then completed a treadmill run to exhaustion at 74 ± 1% vVO2peak, with pulmonary gas exchange measured over the first hour. Interstitial glucose [iG] was measured via continuous glucose monitoring (Supersapiens, Atlanta, USA). Data were analysed ANOVA and post hoc t-tests with Bonferroni adjustment as appropriate, with p ≤ 0.05 accepted as significant. Mean 24-h [iG] was similar between diets (LGI:102 ± 5 vs. HGI:100 ± 5 mg/dL). [iG] variability measures, including standard deviation (LGI:17 ± 1 vs. HGI:18 ± 2 mg/dL, p = 0.016) and coefficient of variation (LGI:16 ± 1% vs. HGI:18 ± 1%, p = 0.0003), were lower in the LGI diet, with a reduced percentage of time spent below the recommended range (LGI 2 ± 1% vs. HGI 4 ± 2%, p = 0.006. Level 1 [55–69 mg/dL] LGI 1 ± 1% vs. HGI 3 ± 2, p = 0.005). Carbohydrate oxidation during the first hour of the run test was reduced in the LGI diet arm (ΔLGI −0.14 ± 0.32 vs. ΔHGI 0.06 ± 0.28 g·min−1, p = 0.016) but endurance capacity was similar across diets. Adopting a 28-day LGI carbohydrate-rich diet and incorporating isomaltulose improved glycaemic variability and reduced time spent below the target glycaemic range with evidence of similar endurance performance capability when compared to a HGI carbohydrate-rich diet.
Keywords: endurance, metabolism, nutrition, performance, physiology
College: Faculty of Science and Engineering
Funders: This study was funded by BENEO as part of a PhD project co-funded by Supersapiens Inc., the Team Novo Nordisk Foundation, and Swansea University.
Issue: 12
Start Page: e70092

Similar Items