The optimal frequency of jogging in terms of mortality risk was shown to be two to three times a week and at a leisurely pace, according to a study published Feb. 2 in the Journal of the American College of Cardiology (JACC). Jogging three times or more a week was not shown to be statistically different from remaining sedentary.
Using data from the Copenhagen City Heart Study, researchers observed the pace, quality and frequency of jogging in 1,098 healthy joggers and 3,950 healthy non-joggers to evaluate the association between jogging and long-term, all-cause mortality. Participants were excluded for a history of coronary heart disease (CHD), stroke and cancer. Participants rated their physical activity on a graded scale of one to four: one, almost entirely sedentary; two: light physical activity 2-4 hours per week; three: vigorous activity for 2-4 hours per week, or light physical activity for more than four hours per week; four: high vigorous physical activity for more than four hours. Joggers were further divided into three subgroups based on dose of jogging: slow (5 mph, 7 mph, >4 hours per week, >3 times per week).
Follow-up of all participants occurred from their first examination in 2001 until 2013, or death (a 12 year followup!).
The results of the study showed that jogging from 1 to 2.4 hours per week was associated with the lowest mortality, while greater quantities of jogging were not significantly different from remaining sedentary in terms of mortality risk. Further, researchers found a U-shaped association between jogging and mortality. Researchers reported 28 deaths among joggers and 128 among sedentary non-joggers, though no causes were recorded.
The authors conclude that “the U-shaped association suggests the existence of an upper limit for exercise dosing that is optimal for health benefits…If the goal is to decrease the risk of death and improve life expectancy, going for a leisurely job a few times per week at a moderate pace is a good strategy.”
In an accompanying editorial comment, Duck-chul Lee, PhD, Department of Kinesiology, College of Human Sciences, Iowa State University, adds that the study “adds to the current body of evidence on the dose-response relationship between running and mortality. However, further exploration is clearly warranted regarding whether there is an optimal amount of running for mortality benefits, especially for cardiovascular and CHD mortality. In addition, because self-reported doses of running may induce measurement error and bias, it would be preferable to use an objective assessment of doses of running in future studies.”
Valentin Fuster, MD, PhD, MACC, editor-in-chief of JACC, remarks that “this study attempts to answer the question about whether increased intensity among better trained individuals results in improved outcomes. What is most interesting in this paper is the U-shaped curve of the findings, indicating that moderate exercise, with regard to total duration, frequency and intensity, results in the best benefit. Thus, it was fascinating to see that both the sedentary population and the aggressive exercisers (with regard to frequency, duration and speed) have higher mortality rates than the moderate exercisers.”
So, slow down a little if you are jogging too fast and too much! Soak in the surrounding and enjoy the jog at a leisurely pace!