Missed a day of exercise? No sweat, literally and figuratively. Researchers at the UT Southwestern Medical Center have found that a single workout can activate neurons that influence metabolism for up to two days, and the same effects last longer with training. A UT Southwestern news release reports that the researchers measured the effects of short and long-term exercise on two types of neurons in the melanocortin brain circuit, which is shared by both humans and mice. One of the neuron types (POMC) is associated with reduced appetite, lower blood glucose levels, and higher energy burning when activated; the other type (NPY/AgRP) increases appetite and diminishes metabolism when activated. The researchers found that a single bout of exercise can boost the activity of POMC neurons and inhibit the counterpart NPY/AgRP neuron for up to two days, and that those adjustment last longer with more training. The study, which measured brain circuit activity in mice given training regiments that lasted from zero to 10 days, revealed that a single workout (consisting of three 20-minute treadmill runs) decreased appetite for up to six hours. It also found longer-term effects of exercise in the POMC neurons, which improve glucose metabolism when activated. The neurons remained active longer if they also expressed a protein called the leptin receptor.