Related Experiment Video
Updated: May 8, 2026

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults
Published on: December 1, 2023
Effect of the glycemic index of pre-exercise snack bars on substrate utilization during subsequent exercise
Feng-Hua Sun1, John O'Reilly, Liang Li
1Department of Sports Science and Physical Education, The Chinese University of Hong Kong , Shatin , Hong Kong and.
Purpose:
To investigate the effect of the glycemic index (GI) of pre-exercise snack bars on substrate utilization during subsequent moderate intensity exercise.
Methods:
Fourteen male participants (Age: 27 ± 5 yr; BMI: 22.5 ± 2.7 kg m(-2); [Formula: see text]: 48.7 ± 6.1 mL kg(-1 )min(-1)) completed two trials in a randomized and counterbalanced crossover design. Two iso-caloric snack bars with different GI values (20, LGI versus 68, HGI) were provided to the participants. Ninety minutes later, all participants completed 45 minutes of ergometer cycling at 65% [Formula: see text]. Substrate utilization was measured using indirect calorimetry.
Results:
During exercise, higher fat oxidation and lower carbohydrate (CHO) oxidation were observed in the LGI trial (LGI versus HGI: CHO, 87.3 ± 20.1 versus 99.2 ± 19.0 g, p < 0.05; Fat, 15.0 ± 5.8 versus 9.7 ± 7.0 g, p < 0.05).
Conclusion:
Compared with an iso-caloric HGI snack bar, pre-exercise LGI snack bar consumption may facilitate a shift of substrate utilization from CHO to fat during subsequent moderate intensity exercise.
More Related Videos
08:01Measurement of Insulin- and Contraction-Stimulated Glucose Uptake in Isolated and Incubated Mature Skeletal Muscle from Mice
Published on: May 16, 2021
12:59Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People
Published on: July 5, 2017
Related Concept Videos
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are typically...
Metabolic States of the Body: The Postabsorptive State
Initially, glycogen stored in the liver is broken down to release glucose into the bloodstream, while glycogen in the muscles is broken down to supply glucose for energy directly within the muscle cells. As glycogen stores diminish,...
Glucose Homeostasis: Regulation of Blood Glucose
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
Oral Hypoglycemic Agents: Glinides
Hormones Regulating Blood Glucose
In addition to accelerating glucose uptake and utilization, insulin has...
Metabolic States of the Body: Fasting and Starvation