actually low heart is a good thing so long as it related to physcial conditioning and not medical problems:
"Borg's physical conditioning was legendary and unrivalled. He could outlast most of his opponents under the most grueling conditions. Contrary to popular belief, however, this wasn't due to his exceptionally low resting heart rate, often reported to be near 35 beats per minute. In his introduction to Borg's autobiography My Life and Game, Eugene Scott relates that this rumor arose from a medical exam the 18-year-old Borg once took for military service, where his pulse was recorded as 38. Scott goes on to reveal Borg's true pulse rate as "about 50 when he wakes up and around 60 in the afternoon."Borg is credited with helping to develop the style of play that has come to dominate the game today.