BLOOD GLUCOSE RESPONSE BEFORE AND DURING EXERCISE: THE EFFECTS OF FASTING AND MEALS WITH HIGH AND LOW GLYCEMIC INDICES

Journal Title: Medicina Sportiva - Year 2013, Vol 17, Issue 2

Abstract

Objective: This study aimed to investigate the effects of 60-minute running in a fasting state compared to ingesting low and high glycemic index (GI) breakfasts one hour prior to exercise on plasma glucose and physiologic parameters in physically active adults. Methods: Fifteen men completed three trials in a randomized counterbalanced order. One hour before the run, follow¬ing an overnight fast, each participant consumed a high GI (GI = 70) or a low GI (GI = 37) breakfast meal or performed the trial in a fasting state (FAST). Each trial consisted of a 60-minute run at 70% heart rate reserve on a motorized treadmill. Plasma glucose was measured at fast, at each 15-minute postprandial, and during the exercise period. Ratings of perceived exertion, stomach fullness, thirsty sensation and blood pressure were recorded. Results: Following ingestion of high- and low-GI meals, plasma glucose concentrations increased in both trials and peaked at 15 minutes during the postprandial period (8.3 ± 1.2 mmol.L-1 and 7.6 ± 0.8 mmol.L-1, respectively). At 15 minutes of exercise, plasma glucose decreased below fasting values in both breakfast trials and was significantly lower (P < 0.05) than in FAST. Plasma glucose was not different between trials after 15 minutes of exercise. There were no differences in physiologic and self-reported parameters during exercise among the trials.Conclusions: We conclude that one-hour running in a fasting state or following a 60-minute rest after high or low GI meal ingestion does not cause hypoglycemia or anticipate fatigue in non-athletes.

Authors and Affiliations

Janaína Altoé, Rafael da Silva, Guilherme Artioli, Rita de Cássia Alfenas, Valéria de Faria, Lawrens Cardozo Makkai, João Bouzas Marins

Keywords

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  • EP ID EP74209
  • DOI -
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How To Cite

Janaína Altoé, Rafael da Silva, Guilherme Artioli, Rita de Cássia Alfenas, Valéria de Faria, Lawrens Cardozo Makkai, João Bouzas Marins (2013). BLOOD GLUCOSE RESPONSE BEFORE AND DURING EXERCISE: THE EFFECTS OF FASTING AND MEALS WITH HIGH AND LOW GLYCEMIC INDICES. Medicina Sportiva, 17(2), 60-66. https://europub.co.uk/articles/-A-74209