For more than three decades, jogging has been a favorite exercise, but some debate has arisen as to the potential risks of this strenuous form of fitness. Peter Schnohr, from, the Bispebjerg University Hospital (Denmark), and colleagues analyzed a subset of data compiled from the Copenhagen City Heart Study relating to the mortality of 1,116 male joggers and 762 female joggers, as compared to the non-joggers in the main study population. All participants were asked to answer questions about the amount of time they spent jogging each week, and to rate their own perceptions of pace (defined as slow, average, and fast). The first data was collected between 1976 to 1978, the second from 1981 to 1983, the third from 1991 to 1994, and the fourth from 2001 to 2003. For the analysis participants from all the different data collections were followed using a unique personal identification number in the Danish Central Person Register. Results showed that in the follow-up period involving a maximum of 35 years, 10,158 deaths were registered among the non-joggers and 122 deaths among the joggers. Analysis showed that risk of death was reduced by 44% for male joggers (age-adjusted hazard ratio 0.56) and 44% for female joggers (age-adjusted hazard ratio 0.56). Furthermore the data showed jogging produced an age adjusted survival benefit of 6.2 years in men and 5.6 years in women. The investigators found that jogging between one hour and two and a half hours a week, undertaken over two to three sessions, delivered the optimum benefits, especially when performed at a slow or average pace.
