The Study
Enhanced glucose production in norepinephrine and palmitate stimulated hepatocytes following endurance training
This study looked at liver cells from rats that were either trained to run or not. It found that the liver cells from trained rats made more sugar when given certain signals, like stress hormones. But this doesn’t prove it happens the same way in people — it just shows a possible reason why exercise might help control blood sugar in animals.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When rats train a lot, their liver cells get better at making sugar from building blocks like lactate, especially when given signals like norepinephrine or fat.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 515 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This shows how intense training might raise blood sugar even in healthy animals, which could look like early diabetes but is actually a normal adaptation.
- 2Trained rat liver cells made 69% more sugar without any signal.
- 3With norepinephrine, they made 86% more sugar.
- 4They also took in 147% more lactate.
- 5Fat (palmitate) made sugar levels jump as much as the strongest norepinephrine dose.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Physiology
Year
2024
Authors
K. Sumida, Vera M. Lordan, Casey M. Donovan
Related Content
Claims (6)
Female rats that did treadmill training for 10 weeks made more glucose in their liver cells, even when resting and without hormones, compared to rats that didn’t train.
Liver cells from female rats that were trained for endurance produce way more sugar when triggered by a stress hormone, compared to liver cells from untrained rats — showing their bodies are better tuned to respond under stress.
In female rats that were trained for endurance, their liver cells used more lactate to make glucose when stimulated, and this extra fuel use completely explains why they made more glucose—meaning the key change was how much lactate got into the cells, not how fast the cells processed it.
After 10 weeks of endurance training, female rat liver cells become more sensitive to a stress hormone called norepinephrine, meaning they start producing more sugar with much smaller amounts of the hormone compared to untrained rats.
In rat liver cells, a type of fat called palmitate boosts sugar production just as much as a stress hormone does, and adding both together doesn’t do more — suggesting they work through the same switch in the cell.
Doing really intense endurance workouts might raise your blood sugar levels and make it look like you have diabetes, even if your body is actually super healthy.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.