Music Can Enhance Exercise-induced Sympathetic Dominancy Assessed by Heart Rate Variability.
http://www.ncbi.nlm.nih.gov/pubmed

Abstract
Many studies have been conducted on physiological responses of music, yielding controversial results. In the present study, we examined whether music affects the exercise-induced changes in the autonomic nervous system activity in twelve healthy female college students. On the first day, the subjects were asked to rest, exercise, and then rest for 15 min, respectively. On the second day, they were asked to rest with music, exercise, and then rest with music for 15 min, respectively. Heart rate variability was measured for the pre- and post-exercise periods. Music was given according to subjects’ preferences using a vibroacoustic apparatus (body sonic system), i.e. a chair on which subjects laid and felt low-pitch sounds by their body in addition to listening music. With music, ratio of low frequency to high frequency component of heart rate variability (LH/HF) was significantly increased after exercise as compared with before exercise (p < 0.01). By contrast, the changes in LH/HF were not significant without music (p > 0.05). It is suggested that after exercise in which sympathetic nerve activity is dominant, preferred music synchronizes with the activated physical response, further promoting the response and increasing sympathetic nerve activity. Combining music with exercise is therefore not only enjoyable in terms of mood but also may promote physiological excitation and enhance physical activation.