High blood sugar can reduce the benefits of aerobic exercise
Some benefits of aerobic exercise may be reduced by high blood sugar levels. Every doctor recommends regular aerobic exercise, as a higher aerobic capacity is important to achieve better overall health. But scientists at the Joslin Diabetes Center have now discovered that some benefits of aerobic exercise may be diminished or even nullified by higher blood sugar levels. These aspects are observed in people with high blood sugar who are in the “prediabetes” phase, says Sarah Lessard, PhD student, researcher at Harvard Medical School and lead author of this paper.
Clinical studies have shown that people with diabetes or a chronic high blood sugar make great efforts to improve their aerobic exercise capacity, compared to people with normal blood sugar. “The idea behind this study was to see if by increasing blood sugar in mice, the property of improving their aerobic capacity will be affected”, says Lessard. The study also looked at the mechanisms that can lead to a low level of fitness in people with hyperglycemia.
The research team used two groups of mice, whose profile reflects the two major causes of hyperglycemia in humans. A group of mice ate a Western diet high in sugar and saturated fats, which caused weight gain, in addition to hyperglycemia. The other group was stimulated to produce less insulin, which caused similar increases in blood sugar to those in the Western diet, even though the mice had a lower diet in sugar and fat and maintained normal body weight. Both groups underwent a training protocol in which they ran to increase their aerobic capacity. In both groups, the animals ran about 500 kilometers during the study, but those with hyperglycemia failed to improve their aerobic exercise capacity compared to mice with lower blood sugar levels.
Analyzing the skeletal muscles in these hyperglycemic mice, the researchers found that the muscle did not adapt to the aerobic challenge as would normally happen.
“Muscle tissue can reshape itself, which is why exercise becomes easier when we do it regularly,” says Lessard. “Over time, aerobic exercise such as running or swimming can change muscle fibers to become more efficient in using oxygen during exercise. The muscles of hyperglycemic animals have larger fibers and fewer blood vessels, which is more typical of strength training than aerobic training”, says Lessard.
The good news is that in cases of hyperglycemia, mice have failed to improve their aerobic fitness training and have achieved other important health benefits from exercise, including lowering fat and improving glucose metabolism, so regular aerobic exercise is still a key recommendation for maintaining health in people with or without hyperglycemia. It is important to note that people with hyperglycemia may also benefit from other forms of exercise, such as strength training, which is recommended for maintaining good health.
Overall, the study suggests several approaches that could help people with chronic hyperglycemia eventually overcome the obstacles of increasing aerobic capacity. One is to adopt a diet designed to keep blood sugar levels low. Another is to take diabetes medication, which keeps blood sugar levels normal. We often think of diet and exercise as separate ways to improve our health, but experience shows that there is more interaction between these two lifestyle factors than previously known, and it is desirable to consider them together, so as to maximize the health benefits of aerobic exercise. We should strive to maintaing a normal blood sugar level and for this we must choose a healthy diet, such as the one recommended in the Dahna application. If you have problems with your blood sugar, consult a specialist.