Energy Availability and Interstitial Fluid Glucose Changes in Elite Male Japanese Triathletes during Training Camp: A Case Study

• Published in: Nutrients Vol. 16; no. 13; p. 2048
• Main Authors: Hiromatsu, Chiyori, Goto, Kazushige
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.06.2024
• Subjects: Adult; Athletes; Beverages; Blood Glucose - metabolism; Blood sugar; Camps; case studies; Dietitians; East Asian People; Energy; energy expenditure; Energy Intake; Energy Metabolism - physiology; Exercise; Extracellular Fluid - metabolism; Food; Food and nutrition; Glucose; Glucose - metabolism; Health aspects; Humans; Hyperglycemia; Hypoglycemia; Japan; Male; males; Meals; Measurement; Physical fitness; Physiological aspects; Software; Swimming - physiology; Training; Triathlon; Young Adult; Japan; United States > US; energy availability (EA); glucose; triathletes; continuous glucose monitors (CGM)
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu16132048

This study explored the impact of varying energy availability (EA) on the 24-h interstitial fluid glucose concentration (IGC) in five elite male Japanese triathletes at a training camp. Measurements of IGC, energy and macronutrient intake, and exercise energy expenditure (EEE) through metabolic equivalents (METs) from training logs were conducted. Three subjects were evaluated over two 4-day periods, and two subjects over one 4-day period. Findings revealed significant correlations of daily mean nocturnal IGC with daily EA (r = 0.553, p = 0.001) and energy intake (EI) (r = 0.595, p < 0.001). However, no significant correlation was found between mean daily nocturnal IGC and EEE (r = −0.278, p = 0.124). Daytime IGC was ≥110 mg/dL for >50% of the time in all subjects, except on 1 day in one subject, and never fell <70 mg/dL. Therefore, daily EA may influence nocturnal IGC in elite male triathletes, although high daytime IGC levels were maintained without hypoglycemia.