Some devices contain a feature designed to recognize the signs of exercise, such as jumping, and respond by increasing the pacing rate to ensure the heart is beating fast enough during exercise. Sometimes outside influences, like loud concerts, or driving over a bumpy road, can trick the device into thinking exercise is happening, which may result in a higher than necessary pacing rate. This isn't harmful but may feel uncomfortable. If this happens, talk to a doctor as they may be able to change the sensitivity of this feature, or they may be able to disable it without impacting the effectiveness of the device.