Acute exercise does not decrease liver fat in men with overweight or NAFLD

Area of Science:

• Metabolic Health
• Exercise Physiology
• Hepatology

Background:

• Elevated intrahepatic lipid (IHL) content is linked to metabolic complications.
• Prolonged exercise training reduces IHL, but the effect of acute exercise remains unclear.
• Hepatic ATP content may influence insulin resistance and IHL.

Purpose of the Study:

• To investigate the impact of acute exercise on IHL in overweight men.
• To determine if acute exercise alters hepatic ATP content.
• To examine the influence of fasted versus glucose-supplemented states on these changes.

Main Methods:

• Twenty-one overweight men (age 54.8 ± 7.2 years, BMI 29.7 ± 2.2 kg/m²) completed a 2-hour cycling protocol.
• IHL was measured at baseline, 30 minutes post-exercise, and 4 hours post-exercise.
• Hepatic ATP/Total P ratio was assessed at baseline and 4 hours post-exercise under fasted and glucose-supplemented conditions.

Main Results:

• No significant change in IHL was observed within 30 minutes post-exercise in either condition.
• IHL was elevated 4 hours post-exercise compared to baseline in the fasted state (p = 0.010).
• Glucose supplementation blunted the post-exercise increase in IHL (p = 0.789).

Conclusions:

• A single bout of acute exercise does not decrease liver fat in overweight middle-aged men.
• Post-exercise intrahepatic lipid levels can increase, particularly in a fasted state.
• Glucose availability appears to mitigate the rise in IHL following acute exercise.