Related Experiment Video
Updated: Jul 1, 2025

Measurement of Basal and Forskolin-stimulated Lipolysis in Inguinal Adipose Fat Pads
Published on: July 21, 2017
Carbohydrate ingestion does not suppress increases in fatty acid-binding protein 4 concentrations post-acute aerobic
Shigeharu Numao1, Ryota Uchida2, Takashi Kurosaki2
1National Institute of Fitness and Sports in Kanoya, 1 Shiromizu, 891-2393, Kanoya, Kagoshima, Japan. numashige@nifs-k.ac.jp.
Background:
Fatty acid-binding protein 4 (FABP4) has been associated with cardiovascular disease and diabetes. Acute aerobic exercise increases circulating FABP4 concentrations, but the underlying mechanisms remain unclear. The purpose of this study was to investigate the effects of inhibition of lipolysis by carbohydrate ingestion on circulating FABP4 concentrations during and after acute aerobic exercise in healthy men.
Methods:
Men aged between 20 and 40, with no exercise habits and no metabolic diseases, were recruited. In a randomized crossover design, the participants underwent a carbohydrate-ingestion exercise (CE) and a fasted exercise (FE) trial. The CE trial consisted of 40-min acute aerobic exercise with ingestion of carbohydrates and 60-min bed rest. The FE trial followed the same protocol as the CE trial but without carbohydrate ingestion. Venous blood samples were collected to measure hormones (adrenaline, noradrenaline, and insulin) metabolites (glycerol, free fatty acids, and glucose), and FABP4 concentrations. Ventilation and gas exchange were also collected to measure substrate oxidation.
Results:
Thirteen healthy men participated in and completed both the CE and FE trials. The insulin concentration was more than 4 times higher in the CE trial than in the FE trial (p < 0.004, effect size [ES] > 2.00). Free fatty acid concentrations were more than 4 times lower in the CE trial than in the FE trial (p < 0.02, ES > 2.04). However, there was no significant difference in the changes in circulating FABP4 concentrations between the CE and FE trials (p = 0.108), which did not change during aerobic exercise and significantly increased post-aerobic exercise in both trials (p < 0.002, ES > 1.212). Changes in FABP4 concentrations following aerobic exercise were not significantly correlated with changes in glycerol or free fatty acid concentrations during aerobic exercise.
Conclusions:
The results suggest that suppression of lipolysis and elevation of insulin are not strongly involved in increases in FABP4 secretion following acute aerobic exercise.
More Related Videos
11:50Fiber Type and Subcellular-Specific Analysis of Lipid Droplet Content in Skeletal Muscle
Published on: June 8, 2022
04:54Using a Combination of Indirect Calorimetry, Infrared Thermography, and Blood Glucose Levels to Measure Brown Adipose Tissue Thermogenesis in Humans
Published on: June 2, 2023
Related Concept Videos
Metabolic States of the Body: The Absorptive State
Fats as Energy Storage Molecules
Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
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,...
Metabolic States of the Body: Fasting and Starvation