Even slow jogging may reduce risk for death

Issue: March 2015

Regular, light jogging two to three times per week was associated with a significantly lower rate of all-cause mortality compared with sedentary behavior, and light to moderate jogging appeared more beneficial than strenuous jogging, according to a new report.

Perspective from Michael Fredericson, MD

Researchers for the Copenhagen City Heart Study investigated the link between jogging and long-term all-cause mortality in 1,098 healthy joggers (593 men) and 3,950 healthy non-joggers aged 20 to 92 years who were followed through the study since 2001. The researchers specifically analyzed the frequency, pace and quantity of jogging.

Joggers were divided into three groups:

Light joggers: slow or average pace of approximately 5 mph, <2.5 hours/week, frequency of ≤3 times/week.
Moderate joggers: slow or average pace, ≥2.5 hours/week, frequency of ≤3 times/week; fast pace, <2.5 hours/week, frequency >3 times/week or fast pace, ≤4 hours/week, frequency ≤3 times/week.
Strenuous joggers: fast pace of approximately 7 mph, >4 hours/week or ≥2.5 hours/week with frequency of >3 times/week.

Optimal frequency, pace, quantity of jogging

One to 2.4 hours of jogging per week was associated with the lowest rate of all-cause mortality compared with sedentary non-joggers (multivariable HR = 0.29; 95% CI, 0.11-0.8).

The optimal frequency was two to three times/week (HR = 0.32; 95% CI, 0.15-0.69) or one or fewer times/week (HR = 0.29; 95% CI, 0.12-0.72).

A jogging pace that was slow (HR = 0.51; 95% CI, 0.24-1.1) or average (HR = 0.38; 95% CI, 0.22-0.66) was associated with the greatest mortality benefit.

“Many adults will perceive this to be a goal that is practical, achievable and sustainable,” Peter Schnohr, MD, DMSc, from Fredriksberg Hospital, Copenhagen, Demark, and colleagues wrote.

Overall, the lowest risk for mortality was observed among participants classified as light joggers (HR = 0.22; 95% CI, 0.1-0.47), while strenuous joggers had increased risk for all-cause mortality (HR = 1.97; 95% CI, 0.48-8.14). Compared with light joggers, moderate (HR = 3.06; 95% CI, 1.11-8.45) and strenuous (HR = 9.08; 95% CI, 1.87-44.01) joggers had significantly higher HRs for all-cause mortality.

“These findings suggest that there is a U-shaped association between jogging and mortality,” Schnohr and colleagues wrote.

The researchers did not report specific causes of death due to a small number of deaths in each group studied.

“On the basis of current knowledge, if the goal is to decrease the risk of death and improve life expectancy, going for a leisurely jog a few times per week at a moderate pace is a good strategy,” they wrote. “Higher doses of running are not only unnecessary but may also erode some of the remarkable longevity benefits conferred by lower doses of running.”

Further exploration warranted

In an accompanying editorial, Duck-chul Lee, PhD, from the department of kinesiology, College of Human Sciences, Iowa State University, Carl J. Lavie, MD, from the department of cardiovascular diseases, John Ochsner Heart and Vascular Institute, Ochsner Clinical School-The University of Queensland School of Medicine, New Orleans, and Rajesh Vedanthan, MD, MPH, from the Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, said these findings add to the “current body of evidence on the dose-response relationship between running and morality.

“However, further exploration is clearly warranted regarding whether there is an optimal amount of running for mortality benefits, especially for CV and CHD mortality. … The general consensus of the data certainly suggests that ‘More is not better!’ regarding running and mortality. However, we still need more data to truly determine ‘Is more actually worse?’ regarding exercise dose and prognosis,” the authors wrote.

For more information:

Lee D, et al. J Am Coll Cardiol. 2015;doi:10.1016/j.jacc.2014.11.022.

Schnohr P, et al. J Am Coll Cardiol. 2015;doi:10.1016/j.jacc.2014.11.023.

Disclosure: The researchers and editorial authors report no relevant financial disclosures.

Perspective

Michael Fredericson, MD

What this study adds to the knowledge base is that more intense running does not necessarily benefit your health, and could potentially harm your health. However, it is difficult to make a direct cause-and-effect statement based on this study because the number of runners doing more strenuous exercise was relatively low.

The accompanying editorial by Lee and colleagues offers a helpful message for our patients: Even light-to-moderate jogging may be associated with significant health benefits. We want to make sure that patients understand that some exercise is clearly better than no exercise.

There are several things that are unclear from the Copenhagen City Heart Study. One, the researchers only looked at deaths from all causes. It would have been helpful to know what particular causes of death were more likely with more intensive running and which health benefits were more likely. Two, there were only 47 joggers in this study who were running more than 4 hours per week and only 80 who were running more than three times per week. Those are small numbers to be making drastic statements about more intensive running being bad for your health. It would be great if this study could be repeated with larger numbers. There are many other studies that have shown that long-time runners, even those who run significant mileage, live longer and have less health problems overall than those who do other forms of exercise or no exercise.

I worry that the results of this study could be interpreted by patients in the wrong way. They need to understand that exercise is good, and that they may not need to do a lot to obtain good benefits for their health. As health care professionals we should make sure that that is not lost in interpretation.

Michael Fredericson, MD

Director of Physical Medicine and Rehabilitation

Stanford Health Care

Disclosures: Fredericson reports no relevant financial disclosures.