Abstract details
| Abstract-ID: | 1943 |
| Title of the paper: | Reproducibility of glycaemic responses to exercise in people with and without type 1 diabetes: a systematic review |
| Authors: | Merlo, V., Horner, K. |
| Institution: | University College Dublin |
| Department: | Institute for Sport and Health |
| Country: | Ireland |
| Abstract text | INTRODUCTION: Understanding the reproducibility of glucose responses to repeated exercise is essential for distinguishing true physiological variability from random variation and to better inform personalised rather than generalized exercise and nutrition recommendations around exercise. However, the extent to which glycaemic responses to exercise are reproducible within individuals remains unclear. This study aimed to systematically review the evidence on the intra-individual reproducibility of glycaemic responses to repeated, standardised exercise bouts in individuals with and without Type 1 diabetes (T1D). METHODS: A systematic search of MEDLINE (PubMed), EMBASE (Ovid), and Web of Science was conducted from database inception to January 2026. Studies were included if they examined glucose responses to at least two identical exercise bouts in healthy individuals or people with T1D (age >/= 12 yrs). Reproducibility outcomes included measures such as coefficients of variation, intraclass correlation coefficients, limits of agreement, or within-subject standard deviations. Due to heterogeneity in study design and outcome reporting, a narrative synthesis was performed. RESULTS: Thirteen studies met the inclusion criteria, comprising four studies in healthy adults and nine in individuals with T1D. Exercise modalities, intensities, nutritional states, and standardisation procedures varied widely across studies. Reported reproducibility of glycaemic responses ranged from poor to high in both populations. Moderate to high reproducibility was more commonly observed under tightly controlled laboratory conditions, particularly during fasted, moderate-intensity cycling. However, several studies reported poor reproducibility despite similar levels of experimental control. In healthy individuals, glucose responses to exercise also demonstrated substantial day-to-day variability, indicating inherent biological variability independent of diabetes. One study employed a replicate crossover design (1), demonstrating no association between replicate glucose responses to exercise in healthy adult males. CONCLUSION: Studies investigating the reproducibility of glycaemic responses to exercise in individuals with and without T1D have shown mixed results, which may be influenced by methodological factors. The lack of replicate crossover designs and heterogeneous outcome reporting limits the ability to draw firm conclusions and to quantify true physiological variability. Future research using robust reproducibility-focused methodologies is needed to better inform general and personalised exercise recommendations. 1. Shen T, et al. Med Sci Sports Exerc. 2024 Jan;56(1):63–72. |
| Topic: | Health and Fitness |
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