Diabetes is a major threat to global health and controlling blood sugar levels with physical activity and diet is key to managing or preventing diabetes. A new study at the University of Texas now reveals that the health benefits of exercises could be gained by even less physical activity than previously thought.
The researchers examined the effects of a single bout of exercise on two types of neurons in the brain of mice. The neurons make up the so-called melanocortin brain circuit, which humans share with rodents. The neurons in the circuit are hypothalamic pro-opiomelanocortin (POMC) neurons and neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons.
Earlier studies have linked one neuron referred to as POMC with a lower appetite, reduced blood sugar levels, and a more active metabolism. The second neuron, NPY/AgRP has been associated with an increase in appetite and a slower metabolism.
Scientists had previously studied the properties of these neurons and associated areas in the brain in relation to diet and fasting, but they had not investigated how physical exercise affects these neurons.
The new study examined the brain activity and neuronal firing rate in transgenic mice after a workout consisting of three, consecutive, 20-minute sessions of treadmill running. They found that the single bout of exercise activated rodents’ POMC neurons, but deactivated the appetite-boosting NPY/AgRP neurons, and that these neuronal changes lasted for up to 2 days.
The researchers also trained the mice for periods ranging from zero to 10 days and found that the neuronal effects lasted longer if the training period was longer. Based on these results, it is possible to suggest that getting out and exercising even once in a semi-intense manner can reap benefits that can last for days, in particular with respect to glucose metabolism.
The rodents also lost their appetite after the workout. This effect lasted for up to 6 hours after working out. This could explain why many people do not feel hungry immediately after exercise.
A better understanding of neural links to exercise can potentially help a number of conditions affected by glucose regulation and could one day hold therapeutic benefits for patients, especially for people with diabetes who need improved blood-glucose regulation.