Why the liver needs two fuel doors to keep muscles running during exercise
Disruption of Hepatic Mitochondrial Pyruvate and Amino Acid Metabolism Impairs Gluconeogenesis and Endurance Exercise Capacity in Mice
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When mice exercise, their muscles need lots of sugar. Their liver makes new sugar using building blocks from muscles, like pyruvate and alanine. These go into the liver’s power plants (mitochondria) through special doors. If both doors are broken, the liver can’t make enough sugar, and the mice get tired faster.
Surprising Findings
Single gene deletions had no effect, but double deletion caused major impairment.
Most people assume breaking one key metabolic pathway would cause problems, but here, the body fully compensated — revealing hidden resilience.
Practical Takeaways
Support your liver’s glucose-making ability during long workouts with balanced nutrition, including protein and carbs.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When mice exercise, their muscles need lots of sugar. Their liver makes new sugar using building blocks from muscles, like pyruvate and alanine. These go into the liver’s power plants (mitochondria) through special doors. If both doors are broken, the liver can’t make enough sugar, and the mice get tired faster.
Surprising Findings
Single gene deletions had no effect, but double deletion caused major impairment.
Most people assume breaking one key metabolic pathway would cause problems, but here, the body fully compensated — revealing hidden resilience.
Practical Takeaways
Support your liver’s glucose-making ability during long workouts with balanced nutrition, including protein and carbs.
Publication
Journal
bioRxiv
Year
2023
Authors
Michael R. Martino, M. Habibi, D. Ferguson, Rita T. Brookheart, J. Thyfault, G. Meyer, L. Lantier, Curtis C. Hughey, B. Finck
Related Content
Claims (5)
Mice that had two specific liver genes turned off couldn't keep their blood sugar stable after exercise, and their sugar levels dropped a lot compared to normal mice.
When two specific genes are turned off in the livers of mice, their bodies make less blood sugar—both when resting and exercising—because the liver can't use certain fuel sources as well. This shows those genes are important for keeping blood sugar levels up when the body needs more energy.
When mice are genetically changed so their liver can't take in two key energy-related molecules at the same time, they get tired faster during exercise — but only when both are blocked, not just one.
In mice, when two specific liver genes are turned off, their liver cells don't process energy as well—even during exercise—because they can't get enough fuel, not because they're missing the tools to do the job.
In mice, turning off one of two specific liver genes doesn’t hurt their stamina or blood sugar control after exercise, because their bodies can use backup systems to keep making glucose.