Paradoxical Rise in Hypoglycemia Symptoms With Development of Hyperglycemia During High-Intensity Interval Training in Type 1 Diabetes

Abstract

OBJECTIVE To assess the reliability of self-perception of glycemia during high-intensity interval training (HIIT) in subjects with type 1 diabetes. RESEARCH DESIGN AND METHODS This randomized crossover study included subjects who completed four fasted HIIT sessions. Subjects answered the Edinburgh Hypoglycemia Scale, estimated their blood glucose (BG), and had plasma glucose (PG) collected throughout exercise and recovery. RESULTS As PG increased throughout exercise, hypoglycemia scores increased across each category: autonomic (3.1–4.4, P < 0.05), neuroglycopenic (1.5–2.4, P < 0.05), and nonspecific (1.3–1.9, P < 0.05). Subjects’ estimated BG showed a negative bias that widened as exercise progressed and peaked at −1.6 ± 3.3 mmol/L (P < 0.001) postinsulin correction. CONCLUSIONS During HIIT, despite progressing hyperglycemia, subjects experience increased hypoglycemia symptoms and tend to underestimate their BG level.