Research

Hormonal

Glycemic index does not significantly alter blood glucose or insulin levels during high-intensity exercise, despite differences in the postprandial period.

You do not need to worry about your pre-workout meal causing a blood sugar crash during high-intensity exercise. This study found that blood glucose levels were the same whether you ate a high or low glycemic meal 90 minutes prior. Focus on getting enough carbohydrates overall rather than stressing over the glycemic index.

GoodRefutesHIGH confidence
However, glycemia did not differ by study treatment during exercise.
Paula Guedes Cocate et al. · Nutrition Journal · 2011

Why this rating

Controlled crossover design with precise blood sampling.

Source

Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial

Paula Guedes Cocate et al. · Nutrition Journal · 2011

DOI 10.1186/1475-2891-10-1

crossover · n=15Cited 270×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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