Managing life with diabetes involves many factors , including diet and exercise. Research is ongoing about how diet may interact with other components and affect diabetes risk. A recent study published in Nature Communications explored how the ketogenic diet affected exercise training in mice with high blood sugar. The researchers found that the diet lowered blood glucose levels, improved aerobic exercise adaptation, and even positively impacted the exercising mice’s skeletal muscles. The authors of this study explain that chronic high blood sugar can affect proper adaptation to aerobic exercise. People with high blood sugar may struggle to make improvements in peak oxygen consumption rate , which has to do with the highest level of oxygen the body can use in high-intensity exercise. Previous research from this group had shown that high blood sugar in mice “impairs aerobic adaptation.” They wanted to see if the ketogenic diet could help restore this in mice that underwent exercise training. The ketogenic diet involves consuming higher amounts of fat and lower amounts of carbohydrates.
Managing life with diabetes involves many factors , including diet and exercise. Research is ongoing about how diet may interact with other components and affect diabetes risk.
A recent study published in Nature Communications explored how the ketogenic diet affected exercise training in mice with high blood sugar.
The researchers found that the diet lowered blood glucose levels, improved aerobic exercise adaptation, and even positively impacted the exercising mice’s skeletal muscles.
The authors of this study explain that chronic high blood sugar can affect proper adaptation to aerobic exercise. People with high blood sugar may struggle to make improvements in peak oxygen consumption rate , which has to do with the highest level of oxygen the body can use in high-intensity exercise.
Previous research from this group had shown that high blood sugar in mice “impairs aerobic adaptation.” They wanted to see if the ketogenic diet could help restore this in mice that underwent exercise training. The ketogenic diet involves consuming higher amounts of fat and lower amounts of carbohydrates.
To test their ideas, they worked with mice with induced high blood sugar and control mice. Some high-blood-sugar mice received a ketogenic diet, while others received a normal diet. The non-high-blood-sugar controls also received a regular diet.
The researchers monitored the mice’s weight and blood sugar levels. Some mice underwent exercise while others remained sedentary. Researchers further tested how switching back to a regular diet following the ketogenic diet affected outcomes. They also had some sedentary mice complete one exercise bout.
Researchers evaluated the mice after the exercise training period, assessing factors such as blood sugar, maximum exercise capacity, and body composition.
Researchers found that mice with high blood sugar on the ketogenic diet had normal blood sugar levels compared to mice with high blood sugar levels on the normal diet, which was high in carbohydrates. Mice with high blood sugar on the ketogenic diet also had blood ketones, indicating the use of fat as an energy source.
Regarding exercise training, all mice, regardless of diet or blood sugar levels, experienced benefits such as improved lean mass and lower random blood sugar levels. The sedentary mice on the ketogenic diet gained fat mass and weight.
For the mice who underwent exercise training and were on the ketogenic diet, the ketogenic diet appeared to cancel out the problems with peak oxygen consumption. In contrast, the high-blood-sugar mice doing exercise training and on a normal diet experienced blunted improvements in peak oxygen consumption.
Problems with skeletal muscle remodeling that occurred in the normal diet and high blood sugar mice that were exercising were not observed in the exercise training mice on the ketogenic diet.
The authors note that this fix in skeletal muscle remodeling could be why there were the observed improvements in peak oxygen consumption. Further research also suggested that ketones may help with this muscle remodeling.
However, exercise performance was about the same for these groups. One possible reason is that the ketogenic group had lower levels of glycogen , which is how the body stores carbohydrates.
Mice on the ketogenic diet had higher rates of fatty acid oxidation , which aids in fatty acid breakdown. In the exercising mice on the ketogenic diet, there also appeared to be greater levels of oxygen use “during the first 10 minutes of maximal exercise testing.”
The results suggest that the change in peak oxygen consumption from the keto diet and exercise training is separate from fatty acid oxidation rates. Sedentary ketogenic diet mice also had higher levels of oxygen use and fatty acid oxidation rates during moderate exercise compared to mice on normal diets. They also had altered levels of certain substances like lactate.
In skeletal muscles of mice on the ketogenic diet, glucose metabolism and transport were downregulated, while fatty acid metabolism and transport were upregulated. The authors also observed changes in the skeletal muscles that they believe indicate the muscles adapt in many ways to a ketogenic diet.
These changes may be the underlying reason they also observed increased fatty acid oxidation. They also observed changes in muscle mitochondria , the cells that create energy, and changes in regulators of blood vessel growth.