A stomach sweat belt is a belt that the user wears around his stomach that causes sweat, either by retaining heat on the stomach during exercise or through the belt's own heating mechanism, depending on the belt. This sweat speeds up weight loss and sometimes makes the user's abdominal muscles temporarily appear more defined. However, since the belt causes only water weight loss, the user gains it back when he rehydrates.
Stomach sweat belts are also known as belly bands, sweat belts and sauna belts. Usage instructions vary depending on the manufacturer, as some manufacturers recommend wearing their belts during normal activities, whereas others design their belts for use during workouts.
Tests of stomach sweat belts have found no benefit to wearing the belts. Since the belts wrap tightly around the abdominal muscles, they allow those muscles to relax during the workout. This leads to those muscles receiving less of a workout, which can result in fewer burned calories.
Dehydration is one possible side effect of stomach sweat belts. Since the belts cause excessive sweating, the user loses water more quickly. If the user doesn't rehydrate sufficiently during or after the workout, it can lead to heat strain, fatigue and even death.