Circulating Fatty Acid-binding Protein 4 Response to Acute Aerobic Exercise in Healthy Men

This study aimed to investigate the association between changes in FABP4 concentration and hormone and metabolite levels during and after acute low- and moderate-intensity aerobic exercise in healthy men. Eleven healthy men (24.4±1.4 years) were administered three trials in random order: 1) low-intensity aerobic exercise trial (LE trial; acute exercise at 40% peak oxygen uptake [Vo₂peak]+bed rest), 2) moderate-intensity aerobic exercise trial (ME trial: acute exercise at 60%Vo₂peak+bed rest), and 3) bed rest (Con trial). Expired gas and venous blood samples were collected at baseline, and immediately, 30 and 60 min after exercise, and substrate oxidation and hormone, metabolite, and FABP4 concentrations were measured. FABP4 concentration did not increase during aerobic exercise in LE and ME trials (p>0.05). However, FABP4 concentration significantly increased after the acute aerobic exercise in both the LE and ME trials (p≤0.003). Increased FABP4 concentration after acute exercise was not correlated with adrenaline, noradrenaline, other hormone, and metabolite concentration changes. These findings suggest that FABP4 concentration increases after acute aerobic exercise independently of exercise intensity. Furthermore, increased FABP4 concentration after acute aerobic exercise may not be involved in the magnitude of adrenaline, noradrenaline, and lipolytic response.